Heat the olive oil in a skillet over medium heat. Add the sliced steak, salt, and pepper. Cook until the steak is browned but not fully cooked through. Remove from heat.

In the crockpot, combine the minced garlic, ginger, sesame oil, brown sugar, soy sauce, and beef broth. Whisk until everything is well combined.

Stir in the browned steak and sliced onions into the sauce in the crockpot. Make sure the steak is well coated.

Cover the crockpot and cook on low for 6-8 hours or set it on high for 3-4 hours until the steak is tender.

About 30 minutes before the cooking time ends, add the sliced bell peppers. They should be tender yet slightly crisp when done.

In a small bowl, whisk together the cornstarch and water to create a slurry. Add this mixture to the crockpot, stirring well to combine. Cook for an additional 30 minutes until the sauce thickens.

Serve the pepper steak over rice or noodles to soak up the rich sauce. Enjoy this cozy and satisfying meal!