Tuna Casserole

1 C. chopped onion
1/2 C. chopped celery
1/4 C. chopped red and green pepper
1 garlic clove, chopped
3 T. soy sauce
1-7 oz. can white tuna
1/2 to 1 C. cooked rice
Mushrooms (optional)
Oil for sauteing (vegetable)

Saute vegetables until tender. Add soy sauce and mix. Add rice and tuna and blend well. Heat and enjoy.