Cowboy Butter Asparagus Flank Steak Crockpot Dinner Tips, FAQ & printable recipe

Tips for success

For the best flavor, use a good-quality au jus mix — the kind that comes in a small packet. If you prefer to make your own, whisk 1 cup beef broth with 1 tablespoon Worcestershire sauce and a pinch of garlic powder.

The slow cooker will concentrate the flavors, so don't add extra salt until you taste the finished dish.

If you want a thicker sauce, remove the beef and asparagus to a platter, then whisk 1 tablespoon cornstarch into 2 tablespoons cold water and stir into the hot liquid.

Cook on HIGH for 10 minutes until thickened. This is a great trick if you're serving the au jus as a gravy over mashed potatoes.

Variations

• Add Mushrooms: Add 8 oz sliced cremini mushrooms along with the beef. They'll cook down and add an earthy flavor that pairs beautifully with the butter and herbs.
• Spicy Kick: Add 1/2 teaspoon red pepper flakes or a chopped jalapeño to the slow cooker for a subtle heat that cuts through the richness.
• Use Chicken: Swap the flank steak for 2 lb boneless, skinless chicken thighs. Cook on LOW for 4-5 hours until tender, and check for 165°F (74°C).
• Vegetarian Version: Replace the beef with 2 cups of hearty mushrooms, like portobello or oyster, and use vegetable broth instead of au jus mix. Cook on LOW for 3-4 hours.

Storage and make-ahead

Fridge

Store in an airtight container in the refrigerator for up to 4 days. Reheat gently with a splash of broth or water.

Freezer

Freeze the cooked beef and sauce in a freezer-safe container for up to 3 months. Thaw overnight in the refrigerator before reheating.

Reheat

Reheat gently in a saucepan over medium-low heat, adding a splash of beef broth or water to loosen the sauce. Avoid boiling to keep the beef tender.

Store leftovers in an airtight container in the refrigerator for up to 4 days. The beef and asparagus will continue to absorb the sauce, so reheat gently in the microwave or on the stovetop with a splash of beef broth to loosen it.

You can assemble the raw ingredients in the slow cooker insert the night before, cover, and refrigerate.

In the morning, place the insert in the slow cooker and cook as directed. Add 30 minutes to the cooking time if starting from cold.

Serving ideas

Serve this cowboy butter flank steak over creamy whipped mashed potatoes to soak up all the buttery au jus.

The potatoes are the perfect canvas for the rich sauce. You can also serve it over rice, egg noodles, or with crusty bread for dipping.

For a complete meal, add a simple green salad or roasted vegetables on the side. The dish is rich, so pair it with something light and crisp. A glass of red wine or a cold beer complements the savory beef and garlic beautifully.

Frequently asked questions

Recipe card

Cowboy Butter Asparagus Flank Steak Crockpot Dinner

Prep 10 minCook 6 hRest 5 minTotal 6 h 15 minServes 6

Ingredients

• 2 lb flank steak, thinly sliced against the grain
• 1 bunch fresh asparagus spears, trimmed
• 6 cloves garlic, smashed
• 2 sticks garlic herb cowboy butter, sliced
• 1 oz au jus mix (dry packet)
• Creamy whipped mashed potatoes, for serving

Instructions

1. Place the sliced flank steak strips in an even layer in the bottom of a 6-quart slow cooker. Scatter the trimmed asparagus spears and smashed garlic cloves over the beef. Top with the sliced garlic herb cowboy butter and sprinkle the au jus mix evenly over everything.
2. Cover the slow cooker and cook on LOW for 6 to 7 hours, or on HIGH for 3 to 4 hours, until the beef is fork-tender and the asparagus is tender but not mushy. Do not stir during cooking; the gentle heat will create a rich, bubbling au jus. Let it rest for 3 minutes before slicing.
3. Turn off the slow cooker. Let the beef rest in the hot liquid for at least 5 minutes before serving. Using a slotted spoon, transfer the beef and asparagus to a serving platter or over whipped mashed potatoes. Spoon the hot au jus over the top.

Contains: milk, gluten

Estimated nutrition per serving

Calories

480

Protein

38 g

Carbohydrates

12 g

Fat

30 g

Automatic estimate from the ingredient list, not laboratory-verified.