Heat oven to 375. Cut sausage into 1/4" slices and brown in skillet; drain.
Combine soup and milk in 3-qt casserole. Stir in pasta, sausage, 1/2 cup cheese, 1/2 cup French Fried Onions and peas.
Bake 30 minutes until hot; stir. Top wityh remaining cheese and onions.
Bake another 3 minutes until golden brown.