Directions

1. Cook the spaghetti and frozen peas according to package directions.
2. In the meantime, place the milk and cream cheese in a saucepan over low heat and whisk the mixture until smooth. Add the Parmesan cheese, onion salt and oregano and stir well to combine.
3. Pour the cheese mixture over the cooked spaghetti, and then add the cooked peas, tuna, mushrooms, pimentos and onion. Mix well to combine and then transfer to a casserole dish.
4. Cover the casserole with foil and then bake in a preheated oven for 20 minutes at 350 degrees F.