|Thin spaghetti||8 Ounce|
|Instant chicken broth/1 chicken bouillon cube||1 Cup (16 tbs)|
|Dry mustard||1 Teaspoon|
|Evaporated milk||1 Can (10 oz)|
|Canned sliced mushrooms||4 Ounce|
|Diced cooked chicken||3 Cup (48 tbs)|
|Grated sharp cheddar cheese||1 Cup (16 tbs)|
|Grated parmesan cheese||1⁄4 Cup (4 tbs)|
Cook spaghetti, following label directions; drain; place in buttered 8-cup shallow baking dish.
While spaghetti cooks, saute onion in butter or margarine until soft in large saucepan.
Remove from heat; blend in flour, instant broth or bouillon cube, salt, dry mustard, and pepper.
Slowly stir in evaporated milk, then liquid from mushrooms plus water to make 1 1/2 cups.
Cook, stirring constantly, until sauce thickens and boils 1 minute; stir in mushrooms and pimientos.
Mix 2 cups sauce with drained spaghetti in baking dish, making a well in center to hold the chicken mixture.
Combine chicken with remaining sauce; spoon into dish with spaghetti; sprinkle cheeses on top.
Bake in hot oven (450Â°) 20 minutes, or until bubbly and golden.
(If made ahead, cover lightly, cool, then chill until 30 minutes before baking. If put into oven cold, allow an additional 15 to 20 minutes' baking time.)