French Onion Roast Beef | Slow Cooker

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This easy French Onion Roast Beef recipe is fall apart tender and has all the French Onion flavor that you love. It is also low carb and paleo-friendly.

Delicious French Onion Roast Beef made in the slow cooker. Get the recipe from Cosmopolitan Cornbread.

I really enjoy making dishes in my slow cooker, especially on days that I am trying to get a lot of work done out on the homestead. I can spend a little time getting it going, then head on out to work, and come in later to dinner practically waiting for me.

But besides the hands-off aspect being a serious time saver, this particular recipe is absolutely packed with flavor. I pair this with some mashed potatoes and a veggie, and dinner is done.

To Make this Recipe You Will Need:

  • beef chuck roast
  • salt
  • black pepper
  • cooking oil
  • onions
  • butter
  • garlic
  • beef broth
  • Worcestershire sauce
  • apple cider vinegar (or red wine vinegar)
  • thyme
  • bay leaf
  • tapioca starch (or cornstarch)
  • cast iron skillet
  • slow cooker
  • plate or platter
  • whisk
  • small dish

To begin, the seasoned roast is seared in a cast iron skillet, to give it that wonderful added flavor.

beef chuck roast in a cast iron skillet

Gobs of sliced onions are then cooked in the same skillet. The onions will absorb all of that goodness that is left in the skillet after your sear the roast, adding even more flavor to the dish.

sliced onions on a cutting board
sliced onions cooking in a cast iron skillet

Once the onions have cooked for a bit, they are layered in with the roast and a few more things are added to create the broth that your roast will cook in.

ingredients for the French Onion Roast Beef

Put the lid on the slow cooker, set it to low, and just walk away.

Several hours later, after you have gone about your day, your gorgeous French Onion Roast Beef is ready to enjoy.

Delicious French Onion Roast Beef made in the slow cooker. Get the recipe from Cosmopolitan Cornbread.

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French Onion Roast Beef | Slow Cooker Recipe

Constance Smith – Cosmopolitan Cornbread
This easy French Onion Roast Beef recipe is fall apart tender and has all that French Onion flavor that you love.
5 from 4 votes
Prep Time 15 minutes
Cook Time 8 hours
Additional Time 10 minutes
Total Time 8 hours 25 minutes
Course Entrées – Main Dishes
Cuisine Paleo
Servings 8
Calories 263 kcal


  • 2 lb beef chuck roast
  • 1/2 teaspoon sea salt
  • 1/2 teaspoon freshly ground black pepper
  • 1 Tb coconut oil, extra virgin olive oil or other preferred cooking oil
  • 3 onions, thinly sliced
  • 1 Tb ghee or butter
  • 2 c beef broth
  • 1 Tb Worcestershire sauce
  • 1 Tb apple cider vinegar or red wine vinegar
  • 3/4 teaspoon dry thyme
  • 3 cloves garlic, minced
  • 1 bay leaf
  • 2 Tb tapioca starch or cornstarch
  • 1/3 c cold water


  • To begin, season your chuck roast on both sides with the salt and pepper.
  • Heat the oil in a large cast iron skillet over medium high heat, until the oil is shimmering and hot, but not smoking.
  • Place your roast in the skillet and let it sit for 3-5 minutes, or until it is nicely seared. Turn it over and sear the other side. Transfer the roast to a dish and set it aside for now.
  • Add the ghee or butter and sliced onions to the skillet and cook on medium low heat for 5-10 minutes, or until the onions are slightly softened and a touch golden.
  • Place half of your onions in the slow cooker.
  • Place your roast into the slow cooker and top with the remaining onions.
  • Add in the beef broth, Worcestershire sauce, vinegar, thyme, garlic, and bay leaf.
  • Cover your slow cooker and set it to low. Cook for 6-8 hours.
  • When your roast has finished cooking, transfer it to a serving platter.
  • Combine the tapioca starch and cold water, whisk them smooth.
  • Turn your slow cooker to high and add the starch water to the broth. Let this cook for a few minutes to thicken up into a gravy.
  • Enjoy!


Serving: 1cCalories: 263kcalCarbohydrates: 7gProtein: 23gFat: 16gSaturated Fat: 8gPolyunsaturated Fat: 1gMonounsaturated Fat: 7gTrans Fat: 1gCholesterol: 82mgSodium: 496mgPotassium: 495mgFiber: 1gSugar: 2gVitamin A: 66IUVitamin C: 4mgCalcium: 40mgIron: 3mg

Nutritional information is auto-generated and the accuracy is not guaranteed.

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2 thoughts on “French Onion Roast Beef | Slow Cooker”

  1. My daughter does not care for the stringyness of a chuck roast even though I love a chuck roast. Is there any other cut of beef I could use?

5 from 4 votes (4 ratings without comment)

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