Sirloin Steak: Slow Cooker Pepper Steak

Ingredients

• 2 pounds beef sirloin, cut into 2 inch strips
• ¾ teaspoon garlic powder, or to taste
• 3 tablespoons vegetable oil
• 1 cube beef bouillon
• ¼ cup hot water
• 1 tablespoon cornstarch
• ½ cup chopped onion
• 2 large green bell peppers, roughly chopped
• 1 (14.5 ounce) can stewed tomatoes, with liquid
• 3 tablespoons soy sauce
• 1 teaspoon white sugar
• 1 teaspoon salt