Add the chopped onions, green bell peppers, stewed tomatoes (with the liquid), soy sauce, sugar, and a pinch of salt and pepper into the slow cooker. Stir everything gently to combine.

1 1/2 pounds of beef sirloin, thinly sliced 1/4 cup of soy sauce 1 cup of beef broth 1 tablespoon of brown sugar 1 tablespoon of sesame oil 3 cloves of garlic, minced 1 onion, sliced 1 green bell ...