Cook the rice according to package instructions. If you have cooked rice already, skip this step.

Heat a little oil in a large pan or skillet over medium-high heat.

Add the sliced chicken tenderloins and cook until browned and cooked through, about 5-7 minutes. Remove chicken from the pan and set aside.

Add the diced onion and carrot to the same pan. Cook, stirring occasionally, until softened, about 3-4 minutes.

Add the diced zucchini to the pan and cook for another 3 minutes until slightly tender.

Return the cooked chicken to the pan with the vegetables.

Stir in the cooked rice and tomato sauce. Mix well to combine everything.

Season with salt and pepper to taste. Cook for another 1-2 minutes, stirring, until everything is heated through.

If using, stir in the sour cream or mayonnaise for extra creaminess.

Serve hot, topped with grated cheese if using.