Bring a large pot of salted water to boil; place noodles in water and bring to boil again. Cook until al dente; drain well.
While noodles are cooking saute in a medium size saucepan vegetable oil, onion, green and red bell peppers. Saute until tender.
Pour soup, tuna, milk, salt and black pepper into the saucepan. Mix well over medium-low heat.
Fold the noodles into the saucepan.
Pour entire mixture into a 2 quart casserole. Sprinkle bread crumbs over the mixture. Bake 20 to 30 minutes or until the top is crisp and golden brown.
