This slow-cooker version of pepper steak transforms economical sirloin into tender, flavorful bites in a rich, savory tomato-based sauce. Bell peppers add sweetness and color, while the sauce thickens into a glossy gravy that’s perfect over rice or noodles. Minimal prep and a long, gentle cook make this an ideal weeknight dinner.
Ingredients
2 lb sirloin steak, cut into thin strips
2 tablespoons olive oil
1 medium onion, chopped
3 cloves garlic, minced
1 cup hot water
1 beef bouillon cube
2 tablespoons cornstarch
½ cup low-sodium soy sauce
2 tablespoons brown sugar
1 (14.5 oz) can diced tomatoes, undrained
1 tablespoon Worcestershire sauce
½ teaspoon black pepper (or to taste)
3 bell peppers (any color), sliced into strips
Instructions
1. Brown the beef
Heat olive oil in a large skillet over medium-high heat. Working in batches if necessary, add the beef strips in a single layer and sear until browned on all sides (about 2–3 minutes per batch). Transfer the browned beef to the slow cooker.
Browning adds depth of flavor but can be skipped to save time if you prefer a truly hands-off recipe.
2. Sauté aromatics
In the same skillet, add the chopped onion and cook for 2–3 minutes until slightly softened. Add the minced garlic and cook for another 30 seconds until fragrant. Transfer the onions and garlic to the slow cooker.
3. Prepare the sauce
In a small bowl, dissolve the beef bouillon cube in the hot water. In a separate bowl, whisk together the soy sauce, brown sugar, Worcestershire sauce, black pepper, and cornstarch until smooth. Combine with the dissolved bouillon.
4. Assemble the slow cooker
Pour the sauce mixture over the beef and onions in the slow cooker. Add the canned diced tomatoes (with their juices). Stir to combine.
5. Cook
Cover and cook on LOW for 6–7 hours or on HIGH for 3–4 hours, until the beef is very tender.
6. Add the bell peppers
About 30–45 minutes before serving, stir in the sliced bell peppers. Cover and continue cooking until the peppers are tender-crisp to your liking.
7. Thicken (if needed)
If you prefer a thicker sauce, remove the lid for the last 15–20 minutes and set the slow cooker to HIGH, or mix an additional 1 tablespoon cornstarch with 2 tablespoons cold water and stir it in.
8. Serve
Serve hot over steamed rice, mashed potatoes, or egg noodles.
Tips & Variations
Meat choices: Sirloin works well, but you can also use flank steak, round steak, or even chuck roast cut into strips.
Extra vegetables: Add sliced mushrooms, carrots, or snap peas along with the bell peppers.
Spicy version: Stir in ½ teaspoon red pepper flakes or a dash of sriracha with the sauce.
Slow cooker size: A 5–6 quart slow cooker works perfectly for this recipe.
Make ahead: Assemble everything (except bell peppers) in the slow cooker insert, refrigerate overnight, then start cooking in the morning. Add bell peppers near the end.
Enjoy your easy, comforting Crockpot Pepper Steak!




