Start by slicing the sirloin steak against the grain into thin strips and chopping the bell peppers into bite-sized pieces.

In a bowl, combine soy sauce, brown sugar, and half of the teriyaki sauce. Add the sliced steak, tossing to coat, and let it marinate for 30 minutes.

Rinse the white rice under cold water until the water runs clear. Cook it according to package instructions, typically around 20-25 minutes.

In a skillet, heat a splash of cooking oil over medium heat. Add the bell peppers and sauté for about 5 minutes until tender. Remove from skillet.

In the same skillet, add the marinated steak strips and cook for about 4 minutes until browned.

Layer the cooked rice in a bowl, followed by the sautéed vegetables and cooked steak. Drizzle the remaining teriyaki sauce on top.

Finish with a sprinkle of green onions and sesame seeds.