Cowboy Butter Asparagus Flank Steak Crockpot Dinner

This Crockpot cowboy butter asparagus flank steak is the dinner that keeps giving: you layer raw beef, asparagus, garlic, and butter in the slow cooker, sprinkle on some au jus mix, and walk away.

Hours later, the beef is fork-tender, the asparagus is silky, and the bubbling garlic herb butter au jus is begging to be spooned over mashed potatoes. It's a complete, satisfying meal with almost zero effort.

This recipe takes the classic steakhouse combination of cowboy butter and asparagus and turns it into a hands-off slow cooker dinner. Thinly sliced flank steak cooks low and slow with fresh asparagus, smashed garlic, and a generous amount of garlic herb cowboy butter.

A packet of au jus mix adds deep savory flavor and creates a rich, glossy sauce. Serve it over creamy mashed potatoes for a meal that feels indulgent but comes together with just 10 minutes of prep.

Ingredients

Why this recipe works

The slow cooker does all the work here. Flank steak is a lean cut that can be tough if cooked quickly, but low, slow heat breaks down its connective tissue, turning it meltingly tender. The butter and au jus create a self-basting environment, so the beef stays moist and flavorful.

Cooking the asparagus right along with the beef means it absorbs all the buttery, garlicky juices.

The long cook time softens the asparagus until it's almost velvety, and the garlic cloves become sweet and mellow. The result is a one-pot meal where every component complements the others.

Notes and substitutions

Use a good-quality garlic herb cowboy butter — it's often sold in tubs or logs at the grocery store.

If you can't find it, mix 4 tablespoons softened butter with 1 teaspoon garlic powder and 1 teaspoon dried parsley, thyme, or rosemary. The butter adds richness and flavor, so don't skip it.

For the beef, flank steak is ideal, but sirloin or skirt steak also work well. Slice it thinly against the grain before cooking so it's easy to eat. If you prefer less fat, trim any large pieces of fat, but a little marbling helps keep the meat tender.

• flank steak: sirloin or skirt steak, thinly sliced
• asparagus: green beans or broccolini
• garlic herb cowboy butter: 4 tbsp butter mixed with 1 tsp garlic powder and 1 tsp dried herbs
• au jus mix: 1 cup beef broth plus 1 tbsp Worcestershire sauce

Equipment

• 6-quart slow cooker
• Cutting board
• Chef's knife
• Measuring spoons
• Serving spoon