Tomahawk Prime Rib with Garlic Onion Butter – Cooking With Fire
A tomahawk prime rib is a two bone cut that weighs about 6 lbs, and I like to cook it opposite to how you would cook a large steak. Sear it over high heat on all sides and the edges to render and crisp the outside fat. Then lower your grill to 275°F and let the steak cook slow to 135°F internal. During this time you will make the compound butter. Roasted garlic, white onion diced fine and sautéed down with some soy sauce, fresh thyme, rosemary and parsley, all blended with a stick of butter. Once your steak has rested for 20 minutes, separate it into two steaks and melt the butter into both. My Grilled Tomahawk Steak with Roasted Garlic and Herb Butter is a single tomahawk cooked in reverse.
You can use any two bone prime rib if you are unable to find one with the long bone. It’s just there for the photo.
Season the night before if possible. This is what will make the difference in the crust.
Quick Look: Tomahawk Prime Rib with Garlic Onion Butter
- Method: Forward sear over high heat, then finish at 275°F on indirect. Blend the compound butter while it cooks
- Sear: High heat, all sides and edges, until you have a dark brown crust and the outside fat has rendered
- Finish: 275°F indirect until 135°F internal for medium rare. See the chart below for the rest
- Time: 2 to 4 hours depending on thickness and starting temp. Rely on your thermometer, not the clock
- Rest: At least 20 minutes
- Serves: 6 to 8
- The one thing that matters most: Dry brine your steak the night before. Salted and left uncovered in the fridge, the surface dries and you get an even sear around the whole steak
Check out my Garlic Herb Butter Crusted Tomahawk Rib Roast if you want to smoke this cut instead of forward searing it.
Why This Recipe
- Forward sear. By searing your steak first you are allowing the outside fat to render and crisp. Since the steak is still cold in the middle, the 275°F finish brings it up slowly without cooking the crust any further.
- Two steaks from one cut. A two bone tomahawk is two ribeyes that share a cap. When you cut it apart you will have two steaks to serve, and both got the full cook.
- Roasted garlic and sautéed onion. The garlic is roasted and the onion is sautéed down. Both add a sweetness to the butter, and both blend smooth in the food processor.
- Butter on the cut side. When your steak is resting, add the butter to the cut side of the steak. This allows the butter to melt into the steak instead of just resting on top.
- Dry brine. Dry brining your steak the night before allows the surface to dry. You will get an even sear all over.
This is the cut I like to reach for when I want to impress. It feeds a table, I carve it at the table, and it only needs one pan of sides next to it.
Key Ingredients
For the Tomahawk Prime Rib
- Two bone prime rib tomahawk. Will weigh approximately 6 lbs. Use a normal two bone prime rib if you cannot find a tomahawk.
- Steak seasoning. To taste. Use whatever you like, or salt, pepper and garlic powder.
For the Roasted Garlic and Onion Compound Butter
- Unsalted butter. 1 stick, 1/2 cup. Softened.
- Garlic. 1 head. Roasted.
- White onion. 1 medium. Finely diced. Using this instead of shallot.
- Olive oil. 1 tbsp. Divide it between the garlic and the onion.
- Fresh parsley. 1 tbsp. Finely chopped.
- Fresh rosemary. 1 tsp. Finely chopped.
- Fresh thyme. 1 tsp. Leaves only.
- Soy sauce. 1 tsp. You will sauté the onions with this.
- Salt. 1/2 tsp. To taste.
- Pepper. 1/2 tsp.
Similar to my Smoked Garlic Butter, but adding onion that has been sautéed down.
Substitutions or Additions
- Use a bone in ribeye. A bone in ribeye that is 2 inches thick or more can be forward seared and finished at 275°F. It will cook much faster than a tomahawk. Check out my Grilled Bone in Ribeyes and Smashed Parmesan Potatoes for a weeknight meal.
- Use shallots. Swap out the white onion for 2 shallots and sauté them down the same way. This is how I normally make this butter.
- Yellow onion. Swap the white onion for yellow. It will have a similar sweetness.
- Dried herbs. Use 1/3 the amount. Rosemary and thyme can be swapped for dried. Leave the parsley fresh or omit it.
- Add spice. 1 tsp of red chili flakes can be added to the food processor. The butter on my The Best Tomahawk Steak goes in that direction.
- Oven finish. After you sear your steak, let it finish in the oven at 275°F. Place it on a rack above a sheet pan and cook to temp.
- Smoked finish. Smoke the steak at 275°F with a chunk of wood. Since the steak was forward seared, the smoke will only add flavor.
How to Make Tomahawk Prime Rib with Garlic Onion Butter (Step by Step)
Season your steak. Apply a heavy amount of seasoning to all sides of your steak. Seasoning the night before and letting it dry in the fridge will give you a better sear. Place your steak uncovered on a wire rack in your fridge for 12 to 24 hours.
Roast the garlic and sauté the onion. Remove the top of the garlic to show the cloves. Place it on a piece of aluminum foil, drizzle with some olive oil, and season with salt, pepper and garlic powder. Wrap tightly and place in the oven, air fryer or on the grill at 400°F for 45 minutes to an hour, until the garlic is soft and squeezes out of the skin. Let it cool. Add the remaining olive oil to a skillet on medium low. Add your diced onion and cook for 10 to 15 minutes, stirring occasionally, until it has cooked down and is soft. Add the soy sauce and continue to cook until all the liquid has evaporated. Let it cool.
Blend your butter. Add your softened butter, roasted garlic, onion, parsley, rosemary, thyme, salt and pepper to a food processor. Blend until all the ingredients are minced and evenly distributed. Taste your butter and adjust the seasoning if needed. Place in a bowl and refrigerate until your steak is ready.
Onto the hot grill. Get your grill as hot as it will go. Lay the tomahawk on the grates over direct heat.
Sear your steak. Sear your tomahawk on all sides and the edges. You want to develop a crust and let the fat render on the outside. Stand it on its edges to get the fat cap. Be aware of flare-ups.
Lower your grill temperature. Set your grill to 275°F and move your steak to the indirect side. Insert your thermometer into the thickest part of the meat.
Cook to temp. Once your steak reaches 135°F it will be medium rare. It will take about 2 to 4 hours including the sear. Use your thermometer and not time.
Let it rest. Remove your steak from the grill and let it rest for 20 minutes.
Separate the steaks. Cut between the bones to split the tomahawk into two steaks.
Butter the cut side. Add a generous amount of butter to the cut side of both steaks and let it melt in while they finish resting.
Slice your steak. Once your butter has melted, flip the steaks and spoon more melted butter over the top. Slice against the grain.
Serve with your favorite sides. Spoon the remaining melted butter over the steak and put the rest on the table to dip. Mac and cheese, Brussels sprouts, potatoes or asparagus.
Internal Temperature Guide
- Rare: 120 to 125°F
- Medium rare: 130 to 135°F. This is where I pull it
- Medium: 140 to 145°F
- Medium well: 150 to 155°F
- Well done: 160°F and up. I do not suggest cooking this cut that far
These temps are after the steak has rested. You can pull your steak a few degrees lower and let carryover cooking finish it. The USDA states that beef should be cooked to 145°F with a 3 minute rest. As you can see, I cook my steak lower than that, and the same goes for most people who order a ribeye medium rare. Up to you. If you want to know how to make the potatoes, check out my Pan Seared Ribeye with Crispy Smashed Potatoes.
Tips From Miguel
Dry brine your steak the night before. By salting your steak and leaving it uncovered in the fridge, it will dry out the surface. You will get a drier crust and an even sear around the entire tomahawk.
Sear your steak first. By searing your steak first you are giving the outside fat time to render. If you were to reverse sear this cut, the fat on the outside would stay soft.
Roast your garlic ahead of time. Roasting the garlic will take about an hour. Either roast it the day before, or put it on the grill while your steak is cooking.
Dice your onion and let it cook down. When you add the onion to your food processor you want it minced. If your onion is in chunks or still wet, your butter will not be smooth.
Add the butter to the cut side of the steak. Once your steak is separated, place a dollop of butter on the cut side. This lets the butter soak into the steak. Once it’s melted, flip the steak and melt more butter on top.
Watch for flare-ups. Your steak will drip a lot of fat while searing. If your grill starts to flare up, move the steak to the other side until the fire dies down, then go back to it.
Storage and Reheating
- Fridge: Leftover steak will last 3 to 4 days in an airtight container. Your butter will last about a week.
- Freezer: You can freeze your steak for up to 2 months. Your butter can be frozen for 3 months.
- Reheat: Place your slices in the oven at 275°F until warm. You can sear the slices in a hot skillet if you want to crisp them back up.
- Make ahead: Season your steak the night before. You can roast the garlic and make the butter ahead of time.
Leftovers will be good on anything. Try my Baked Mac and Cheese on the Grill with some of the butter on top.
More Beef Recipes to Try
Tomahawk Prime Rib with Garlic Onion Butter FAQs
What is a tomahawk prime rib?
A two bone prime rib with the rib bones left long and cleaned of meat. It is the same cut as a two bone prime rib roast, and the same meat as two bone in ribeye steaks still attached to each other. The long bones are there for display. A regular two bone prime rib cooks exactly the same way.
Should I sear my tomahawk before or after cooking?
I like to sear my tomahawk first. Since the cut is so thick and has a lot of fat, I want it to render before I slow cook the steak. You can also reverse sear your tomahawk, which is what I do on a single tomahawk steak.
How long does a two bone tomahawk take to cook?
About 2 to 4 hours at 275°F, depending on how thick it is and the starting temp. Always use your thermometer and pull it at 135°F for medium rare.
Can I make the compound butter ahead of time?
Yes. Roast the garlic and sauté the onion a day or two ahead and blend the butter. Store it covered in the fridge until your steak is ready. The flavor is better after it sits.
What can I serve with a tomahawk steak?
Any side dish will go with a tomahawk. Some of my favorites are mac and cheese, Brussels sprouts, potatoes and asparagus.
Tomahawk Prime Rib with Garlic Onion Butter
Ingredients
Equipment
Method
- Season the tomahawk heavily on all sides and edges. Set it uncovered on a wire rack in the fridge for 12 to 24 hours. If short on time, season right before cooking.
- Cut the top off the garlic head to expose the cloves. Set on foil, drizzle with a little of the olive oil, season with salt, pepper and garlic powder, wrap tightly, and roast at 400°F in the oven, air fryer or grill for 45 to 60 minutes, until soft. Cool.
- Heat the remaining olive oil in a skillet over medium low. Add the diced onion and cook 10 to 15 minutes, stirring occasionally, until soft and cooked down. Add the soy sauce and cook until the liquid is gone. Cool.
- Add the softened butter, roasted garlic squeezed from its skins, cooled onion, parsley, rosemary, thyme, salt and pepper to a food processor. Blend until minced and even. Taste, adjust, and refrigerate in a small bowl until the steak is ready.
- Heat the grill to high. Sear the tomahawk on all sides and edges until a deep brown crust forms and the outside fat has rendered. Watch for flare-ups.
- Lower the grill to 275°F and set up for indirect heat. Move the tomahawk to the indirect side and insert a thermometer into the thickest part, away from the bone. Cook until 135°F internal for medium rare, about 2 to 4 hours total depending on thickness and starting temperature. Go by temperature, not time.
- Rest at least 20 minutes. Cut between the bones to separate the two steaks. Put a generous dollop of compound butter on the cut side of each and let it melt in as they rest.
- Flip the steaks crust side up, spoon melted compound butter over the top, and slice against the grain. Spoon more butter over the slices and serve the rest on the side for dipping.
