Hamburg, as in hamburger, not German-style.
Pay-per-view sources show hamburg stroganoff showing up on school lunch menus around 1957.
1/2 lb. lean ground beef
1 Tbsp. butter or margarine
4 oz. can sliced mushrooms, drained
2 Tbsp. chopped onion
2 Tbsp. flour
1-1/2 cups beef broth
1/2 tsp. salt
1 Tbsp. catsup
1/2 cup sour cream
8 oz. (4 cups) rigatoni or elbow macaroni
Minced parsley (optional)
In a skillet, lightly brown the beef in butter, stirring to separate. Add mushrooms and onion; cook a few minutes. Remove from the heat; blend in flour.
Add beef broth, salt, pepper and catsup; cook over low heat 10 minutes, stirring occasionally. Blend in sour cream; heat a minute longer.
Meanwhile, cook macaroni; drain in colander and serve stroganoff over macaroni; sprinkle with parsley. Yields four generous servings.