Cowboy Butter Mushroom Beef Bites: 5-Ingredient Crockpot Dinner Step-by-step instructions

Before you start

Before starting, cut the beef into 1-inch cubes if not already done. Dice the onion and slice the mushrooms. Measure the au jus mix and have the butter sticks ready. No need to brown the beef first—the slow cooker does all the work. Make sure your slow cooker is at least 6 quarts to fit everything comfortably.

Instructions

Layer and Go

1. 1Layer the Ingredients
   Place the cubed beef chuck in the bottom of a 6-quart slow cooker. Spread the condensed cream of mushroom soup over the beef, then scatter the diced onion on top. Add the sliced mushrooms if using. Place the sticks of garlic-herb butter over the mixture, then sprinkle the dry au jus mix evenly over everything.
   Look for The beef is covered with soup, onions, and butter; the au jus mix dusts the top.
   Tip No need to stir—the layers will meld as it cooks.
2. 2Cover and Cook Low
   Cover the slow cooker with the lid. Cook on LOW for 8 to 10 hours, or on HIGH for 4 to 5 hours, until the beef is fork-tender and easily shreds.
   Look for The sauce will be bubbling gently around the edges.
   Tip Low and slow gives the toughest cuts time to become tender.

At the end of this phase, all ingredients are in the slow cooker, with the beef on the bottom and the butter and au jus on top. The raw beef is pink, the onions are white and crisp, and the butter is cold.

The aroma is a mix of raw beef, onion, and the savory scent of the soup and au jus. No heat yet—just a colorful, ready-to-cook setup.

Slow Simmer

3. 3Check the Beef
   After the minimum cooking time, check the beef by piercing a cube with a fork. It should slide off the fork easily and break apart with light pressure. If not, continue cooking in 30-minute increments until tender. Let it rest for 3 minutes before slicing.
   Look for Beef is tender and easily shredded.
   Safe temperature 145°F (63°C) internal temperature (steaks, chops and roasts)
   Tip If using a thermometer, the beef should read at least 145°F (63°C) for safety, though it will be much higher after long cooking.
4. 4Rest the Meat
   Turn off the slow cooker and let the beef rest in the hot gravy for at least 3 minutes before serving. This allows the juices to redistribute and the meat to stay moist.
   Look for The sauce settles and thickens slightly.
   Safe temperature 145°F (63°C) internal temperature (steaks, chops and roasts)
   Tip Resting is key for tender beef.

After 8 hours on low, the slow cooker is bubbling gently around the edges. The sauce is a rich, golden-brown gravy, and the beef cubes have darkened and begun to fall apart.

The mushrooms are tender and have absorbed the sauce. The smell is deeply savory, with garlic and herbs wafting up. The beef should easily shred with a fork.

Serve and Enjoy

5. 5Serve Over Mashed Potatoes
   Spoon the beef, mushrooms, and onions over warm mashed potatoes, then ladle the rich gravy over the top. Serve hot.
   Look for The beef is glistening with gravy.
   Tip Mashed potatoes soak up the sauce beautifully.

The beef is fork-tender and coated in a glossy, thick gravy. The mushrooms and onions are soft and caramelized. The dish is steaming hot, with a rich, buttery aroma. When spooned over mashed potatoes, the gravy pools around the edges. The beef bites are melt-in-your-mouth, and the sauce is silky and full of umami.

Common mistakes

The most common mistake is opening the lid too often to check on the food. Every time you lift the lid, heat escapes and adds 20-30 minutes of cooking time.

Resist the urge to stir—the layers are intentional and will meld as they cook. Also, if you use lean beef, it can become dry; stick with well-marbled chuck. Finally, don’t skip the resting time; it allows the juices to redistribute.

How to tell it’s done

The beef is done when it is fork-tender and easily shreds with a fork. Insert a fork into a cube—it should slide in with little resistance and the meat should break apart cleanly.

For safety, the beef must reach an internal temperature of at least 145°F (63°C), though after 8 hours on low it will be well above that. Let the meat rest in the hot gravy for at least 3 minutes before serving to keep it juicy.

• Steaks, chops and roasts: 145°F (63°C) in the thickest part, then a 3-minute rest