Begin by slicing the beef sirloin into even strips and patting dry. Season generously with salt and pepper.

In your slow cooker, place the seasoned beef at the bottom and layer chopped onions and bell peppers over it.

In a medium bowl, whisk together minced garlic, beef broth, crumbled bouillon cubes, soy sauce, honey or brown sugar, Worcestershire sauce, ground ginger, salt, and pepper until smooth.

Carefully pour the prepared sauce over the layers of beef and vegetables in the slow cooker.

Cover the slow cooker and cook on LOW for 6-8 hours or HIGH for 3-4 hours until the beef is fork-tender.

For a thicker sauce, mix cornstarch with cold water until smooth and stir into the slow cooker during the last 10-15 minutes of cooking.

Serve the Slow Cooker Pepper Steak over rice, egg noodles, or mashed potatoes, garnished with green onions or sesame seeds.