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Last Updated on November 17, 2021 by Aimee Stock
This Slow Cooker Pot Roast Casserole takes my traditional Slow Cooker Beef Pot Roast Recipe up a notch, adding a box of Au Gratin potatoes. It sounds crazy, but it totally works! This recipe uses the amount of liquid that is called for in the au gratin box mix to cook the beef and veggies. Then, the remaining ingredients (potatoes, sauce mix , butter and milk) are added and cooked until the potatoes are tender. The sauce thickens and you have a one-pot meal. Let me show you how to make it!

How to make my Slow Cooker Pot Roast Casserole
You’ll want to purchase a whole chuck roast or what’s called “stew beef” already cut into cubes. I toss with salt, pepper and a bit of flour, then brown in a heavy bottomed stock pot with a small amount of oil. The beef is not fully cooked at this point, we’re just adding a bit of color and flavor.
Chop the onions and cut carrots into 1/4″ slices.

And….if you have dogs lurking about in the kitchen ever so hopeful for a carrot, be sure to give them one 🙂

I also add Worcestershire sauce and I really feel like you shouldn’t omit it. It adds so much to that beefy flavor.

Turn the slow cooker on high, add 2 cups of water, salt & pepper. Add the par-cooked beef, onions and carrots. Cook until all are tender, about 4 hours.
NOTE: If you are not ready to serve, turn the slow cooker on ‘warm” at this point.

Once cooked, it looks like this.

Add the sauce mixture, milk and butter. Then add the dehydrated potatoes. Stir well to combine.
Cook until the potatoes are tender and cooked through. The sauce should also be slightly thickened.

Garnish with freshly chopped parsley and serve.

Did you make my Slow Cooker Pot Roast Casserole? Leave me a comment below and let me know what you thought. You can also tag me with photos of your creations on Instagram @aimee_stock I always love seeing what you come up with 🙂

Slow Cooker Pot Roast Casserole
Equipment
- Slow Cooker / Crockpot
Ingredients
TO BROWN THE BEEF:
- 1 tbsp Oil
- 1 1/2 lbs Chuck Roast (or "stew beef") cut into 1" cubes
- All Purpose Flour
- Salt & Pepper to taste
FOR COOKING THE BEEF & VEGETABLES:
- 1 medium Onion chopped
- 2 medium Carrots sliced in 1/4" rounds
- 2 c Hot Water
- 2 tbsp Worcestershire Sauce
- Salt & Pepper to taste
TO COOK THE AU GRATIN POTATOES:
- 1 box Au Gratin Potatoes also add the sauce mix
- 1/2 c Milk
- 2 tbsp Butter
FOR SERVING:
- Crusty Bread
- Fresh Parsley chopped, for garnish
Instructions
- If not already using stew beef, cut chuck roast into 1" cubes. Chop the onions and slice the carrots 1/4" thick. Add to the slow cooker.
- In a large, heavy bottomed stock pot over medium high heat, add a tablespoon of oil. Toss the cubes of chuck roast that you have seasoned with salt and pepper with a bit of flour. Turn occasionally until browned on both sides. Remove to the slow cooker. It will not be fully cooked at this point.
- Turn the slow cooker on high, add water, Worcestershire, salt and pepper. Cover and cook for 4 hours or until the beef and vegetables are tender.If not ready to serve, turn the slow cooker on "warm" and continue on to the next step about an hour prior to enjoying.
- Add the milk, butter and seasoning packet from the Au Gratin potatoes. Stir. Then add the potatoes and stir well. Cover and continue to cook until the potatoes are tender.
- Garnish with freshly chopped parsley and serve with your favorite loaf of crusty bread.