Cowboy Butter Green Bean Flank Steak Crockpot Dinner Step-by-step instructions

Before you start

Before you start, slice the flank steak thinly against the grain — this helps it become tender during the long cook. Trim the green beans and dice the russet potatoes into 1-inch cubes so they cook evenly.

If using a store-bought garlic-herb cowboy butter, slice it into rounds; if making your own, combine softened butter with minced garlic and herbs. Have the au jus mix packet ready. No need to preheat the slow cooker; just layer everything in the cold insert.

Instructions

Layer and Set

1. 1Layer the Ingredients
   Place the sliced flank steak strips in an even layer at the bottom of a 6-quart slow cooker. Scatter the trimmed green beans and diced russet potatoes over the beef. Arrange the slices of garlic-herb cowboy butter on top, then sprinkle the au jus mix evenly over everything.
   Look for The beef is covered with beans, potatoes, butter slices, and seasoning.
   Tip No need to stir — layering keeps the beef juicy and lets the flavors meld.
2. 2Cover and Cook Low
   Cover the slow cooker with its lid. Cook on LOW for 8 hours, or on HIGH for 4 hours, until the beef is fork-tender and easily shreds or cuts with a spoon. The potatoes should be soft and the green beans tender but not mushy. Let it rest for 3 minutes before slicing.
   Look for A rich, savory aroma fills the kitchen as the butter melts and the au jus forms a gravy.
   Safe temperature 145°F (63°C) internal temperature (steaks, chops and roasts)
   Tip Resist lifting the lid during cooking — each peek adds 20 minutes to the cook time.

At the end of this phase, you'll see a raw stack of beef, green beans, potatoes, butter slices, and au jus mix in the slow cooker. The butter is still solid, and the seasonings are dry.

The ingredients should be evenly distributed, but there's no need to stir — the slow cooker will handle the mixing as everything melts and simmers.

Slow Cook and Rest

3. 3Check the Meat Temperature
   After the cook time, use an instant-read thermometer to check the thickest piece of flank steak. It should register at least 145°F (63°C). If not, continue cooking in 15-minute increments until it reaches the safe temperature. The meat will be very tender and may shred easily. Let it rest for 3 minutes before slicing.
   Look for The thermometer reads 145°F (63°C) or higher, and the beef is pull-apart tender.
   Safe temperature 145°F (63°C) internal temperature (steaks, chops and roasts)
   Tip Because the meat is cooked low and slow, it will be far more tender than a quick-seared steak.
4. 4Rest the Meat
   Turn off the slow cooker and let the meat rest in the cooking liquid for at least 3 minutes before serving. This allows the juices to redistribute and keeps the beef moist and flavorful.
   Look for The bubbling subsides, and the gravy settles around the meat and vegetables.
   Tip The rest is short but essential — it locks in the juices.

After 8 hours on LOW, the slow cooker is filled with bubbling, aromatic gravy. The beef is deeply browned and tender, the potatoes are soft, and the green beans are cooked through. The kitchen smells rich and savory. Before serving, check the meat temperature and let it rest for at least 3 minutes.

Serve and Enjoy

5. 5Serve Over Mashed Potatoes
   Spoon the beef, green beans, and potatoes over creamy whipped mashed potatoes on a dinner plate. Ladle plenty of the garlic-herb butter au jus over the top so every bite is coated in the rich, savory gravy.
   Look for Steaming spoonfuls of beef and vegetables glisten with buttery au jus.
   Tip For a complete meal, add a side of crusty bread to soak up the extra gravy.

When you spoon the beef and vegetables over mashed potatoes and ladle the gravy on top, the dish looks glossy and inviting. The beef should pull apart easily, and the gravy should coat the back of a spoon. Serve immediately while hot, with extra gravy on the side.

Common mistakes

One common mistake is lifting the lid too often to check on the food — each peek releases heat and adds 20 minutes to the cook time. Another is using frozen green beans without adjusting the time, which can turn them mushy.

Also, don't skip resting the meat after cooking; letting it sit in the warm liquid for at least 3 minutes keeps it moist. Finally, avoid overcooking on HIGH if you're not home — LOW is more forgiving.

How to tell it’s done

The dish is done when the flank steak is fork-tender and easily shreds or cuts with a spoon. The internal temperature of the thickest piece should read at least 145°F (63°C) on an instant-read thermometer.

The potatoes should be soft and easily pierced with a fork, and the green beans should be tender but still hold their shape. The gravy will be bubbling and slightly thickened, with a rich, buttery aroma.

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