Brown 1 pound ground beef. Add 3 tbs buter, chopped onion, bell pepper, and celery. Season with pepper flakes, garlic, salt and pepper. Add Ragu sauce, cover and simmer until spaghetti is done.
Meanwhile, bring 2 quarts of water to a boil. Add oil and spaghetti. Cook until slightly tender. Drain spaghetti through a collander, return to pot, and add 5 tsp of butter. Let spaghetti sit for a few minutes, then add Ragu sauce.
Best served the next day.