Finely chop 1/4 cup of white onion. Sweet onions are extra delicious in this. Saute in 2 Tablespoons butter until tender.
Mix together tomato sauce (8 oz can) and 3/4 cup of heavy cream. Stir into soft, sauteed onions.
Heat pasta and leftover seafood (shrimp, scallops, lobster, etc) until just warm. Usually 1 min. in the microwave.
Pour sauce over top and sprinkle with shredded Parmesan cheese.
Serve with a tossed green salad or cup of soup for a perfect light, Springtime meal.