Crockpot Pepper Steak

Ingredients

• 1 1/2 to 2 lbs flank steak (or sirloin, round steak, stew meat, etc.)
• 1 large onion , thinly sliced
• 2 bell peppers (any color), sliced into strips
• 3 cloves garlic , minced
• 1 can (14 oz) diced tomatoes , undrained
• 1/4 cup soy sauce
• 1/4 cup beef broth (or water)
• 2 tbsp oyster sauce
• 2 tbsp brown sugar
• 1 tsp ground ginger (or 1 tbsp fresh ginger, grated)
• 1 tbsp cornstarch (for thickening the sauce)
• 1 tbsp water (to mix with cornstarch)
• Salt
• pepper
• Cooked rice , for serving
• Green onions (optional, for garnish)
• Sesame seeds (optional, for garnish)