Cowboy Butter Pepper Sirloin Tips Slow Cooker Dinner Step-by-step instructions

Before you start

Before you start, pat the steak tips dry with paper towels to help them brown if you choose to sear them first (though this recipe works without searing). Slice the bell peppers into thick strips and cut the red onion into wedges.

If using a homemade cowboy butter, make sure it is softened so it can be easily placed on top of the ingredients. Measure out the au jus mix. Have your slow cooker ready and a serving platter or bowl nearby. This is a true dump-and-go recipe, so the only prep is chopping the vegetables and gathering the ingredients.

Instructions

Layer the Ingredients

1. 1Layer the Beef and Vegetables
   Place the sirloin steak tips in the bottom of the slow cooker in an even layer. Scatter the sliced bell peppers and red onion wedges over the beef, spreading them out so they cover the meat evenly.
   Look for The beef should be mostly covered by the peppers and onions.
   Tip For even cooking, try to arrange the beef in a single layer if possible.
2. 2Top with Butter and Au Jus
   Place the softened cowboy butter on top of the beef and vegetables, breaking it into pieces if needed. Sprinkle the au jus mix evenly over everything.
   Look for The butter and seasoning should be distributed over the surface.
   Tip If the butter is very cold, slice it into thin pats so it melts faster.

At this point, the raw beef is nestled in the slow cooker with the peppers and onions scattered on top. The cowboy butter sits in pats over the vegetables, and the au jus mix dusts the surface. The scene looks colorful and promising—bright red and green peppers, purple onion wedges, and golden butter against the dark beef. The raw meat is still cool, but the aroma of garlic and herbs from the butter is already noticeable. Everything is in place for a long, flavorful simmer.

Slow Cook to Perfection

3. 3Slow Cook Until Tender
   Cover the slow cooker and cook on low for 6 to 8 hours, or on high for 3 to 4 hours, until the beef is fork-tender. The butter will melt into a rich sauce with the au jus and vegetable juices. Let it rest for 3 minutes before slicing.
   Look for The meat should be easily pierced with a fork and the sauce bubbling gently.
   Safe temperature 145°F (63°C) internal temperature (steaks, chops and roasts)
   Tip Avoid lifting the lid during cooking to keep the heat and moisture inside.

After several hours, the slow cooker is filled with a gently bubbling, golden-brown sauce. The butter has melted and blended with the meat juices and au jus, creating a rich, savory liquid that coats the beef and vegetables.

The kitchen fills with an irresistible aroma of roasted garlic, herbs, and beef. The beef is visibly darker and has shrunk slightly, and it yields easily when pressed with a fork. The peppers have softened and taken on a glossy sheen. This is the moment of anticipation before serving.

Serve the Dish

4. 4Serve the Beef and Sauce
   Once the beef is tender, turn off the slow cooker. Use a slotted spoon to transfer the beef and vegetables to a serving platter, then spoon the sauce over the top. Let the beef rest for at least 3 minutes before serving.
   Look for The sauce should be rich and glossy, coating the beef nicely.
   Tip For a thicker sauce, whisk 1 tablespoon cornstarch with 2 tablespoons water and stir into the hot liquid.

The beef and vegetables are lifted out with a slotted spoon, leaving the sauce behind. They are piled onto a serving platter, glistening with buttery juices. The sauce is ladled over the top, pooling around the meat and peppers. The beef is fork-tender, pulling apart with ease, and the peppers are soft but still hold their shape. The dish looks rustic and hearty, with steam rising and the rich scent of garlic and herbs filling the air. It’s ready to be enjoyed.

Common mistakes

One common mistake is lifting the lid to check on the food, which releases heat and extends cooking time. Trust the time range and only check at the end. Another mistake is using frozen meat—thaw it completely in the refrigerator before adding it to the slow cooker to ensure even cooking.

Also, avoid overloading the slow cooker; if it is too full, the ingredients may not cook evenly. Finally, don’t skip the resting time after cooking; it helps the beef retain its juices. If the sauce seems thin at the end, you can thicken it with a cornstarch slurry.

How to tell it’s done

The dish is done when the beef is fork-tender, meaning a fork easily pierces the meat and it shreds or pulls apart with little resistance. The internal temperature of the beef should reach at least 145°F (63°C) for food safety, but because it is cooked low and slow, it will likely be much higher and very tender.

The sauce should be bubbling and slightly thickened, with the butter fully melted and incorporated. The peppers should be soft but not mushy, and they should have absorbed some of the savory flavor. Let the beef rest for at least 3 minutes before serving to allow the juices to redistribute.

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