Prepare Ingredients: Start by slicing your sirloin steak against the grain for tenderness and chop the bell peppers into bite-sized pieces for easy eating.

Marinate Steak: In a bowl, combine soy sauce, brown sugar, and half of the teriyaki sauce. Add your steak slices and let them marinate for at least 30 minutes to absorb those delicious flavors.

Cook Rice: Rinse the white rice under cold water until the water runs clear. Boil the rice according to package instructions, typically about 20-25 minutes until it’s fluffy and ready to soak up those tasty juices.

Sauté Vegetables: In a skillet, heat up some oil over medium heat and sauté the bell peppers for around 5 minutes until they're tender-crisp. Remove them from the skillet and set aside.

Cook Steak: In the same skillet, add your marinated steak and cook for about 4 minutes or until browned, stirring for even cooking.

Assemble Bowl: Layer your cooked rice as the base, followed by the sautéed bell peppers and juicy steak. Drizzle with the remaining teriyaki sauce, and finish with a sprinkle of green onions and toasted sesame seeds.