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French Onion Prime Rib Roast Recipe


Guest Post by Dan Whalen from The Food in My Beard

This French Onion Prime Rib recipe puts all of the flavors from the popular soup on top of a thick and perfectly cooked slice of prime rib! I love getting french onion soup before my dinner at a nice steakhouse, so I thought it would be fun to incorporate the flavors of that soup into the prime rib recipe for my holiday get together.

But how?

The onion part was obvious, I sliced up a few onions and put them underneath the roast while it cooked in the oven, then finished them in a pan for that perfect caramelization.

For the cheese, I wanted it to mimic the browned crust on top of the soup. I achieved this by baking the cheese in the oven to make crisps, and breaking them up on top of the steak.

I also added some buttery croutons to replace the bread that is usually on top of the soup to help the cheese float.

Because the soup traditionally uses beef stock as the base, the prime rib was a natural pairing for the french onion flavors. Caramelized onion and beef is one of my favorite flavor combinations (I can’t make a burger without them!) so you can imagine how much I loved this!  I choose to use a bone-in prime rib roast because it not only adds extra flavor while cooking, but adds a dramatic flair to the presentation which in my opinion is important at holiday get togethers!

In the end, the flavors were spot on for a nice french onion soup, and went really well with the perfectly medium-rare roast.


French Onion Prime Rib Recipe

Prime rib with the flavors of french onion soup
Prep Time30 mins
Course: Main Course
Cuisine: American
Author: Dan Whalen



  • 2 T. dried rosemary
  • 1 T. dried thyme
  • 1 T. coriander
  • 2 T. black peppercorns
  • 2 tsp. chili flakes
  • 2 T. salt


  • Blend the spices in a spice grinder or mortar and pestle. Rub the spices on the roast making sure to cover the whole surface.
  • Preheat oven to 250°F.
  • Put the roast on a rack over a sheet pan and add the onions to the pan. Drizzle the onions with some oil and season with salt and pepper.
  • Cook until the internal temp reaches 125°F for a perfect medium rare. Cooking times are approximate.
    4 lb roast - 3:20
    6 lb roast - 3:50
    8 lb roast - 4:35
  • While the roast rests, add the onions to a frying pan with all the steak juices and cook on medium heat to brown, about 15 minutes. Just before removing them from the heat, add in the honey and stir to combine.
  • Turn the oven to 400°F.
  • Line a sheet pan with parchment and brush with oil. Add cheese in 4 piles. Cook until the cheese is melted and bubbling, about 10 minutes. Remove from the oven.
  • Toss the bread cubes with the melted butter and spread on a sheet pan. Bake for 15 minutes. Remove from oven.
  • Slice the roast and place the portions on individual plates.
  • Top with a scoop of the onions, some croutons, and some pieces of the crispy cheese. Serve.


Dan Whalen is the founder and creator of the popular recipe blog The Food in my Beard. Since the website started in 2008, he has published over 2000 recipes that have been viewed over 50 million times. He has written 4 cookbooks, including books on Tater Tots and S’mores, with his 5th book coming in January 2021. He currently lives in Boston working as a full time blogger and writer. He has appeared on The Today Show, Guy’s Grocery Games, and Hallmark Home & Family. When not working, Dan can usually be found looking for inspiration at concerts, watching Star Wars, eating out with his friends, or playing Super Mario.

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