A good use for boiled ground beef. When you want a meat sauce, heat up a jar or can of spaghetti sauce and add some already cooked ground beef to the sauce and heat through. This is great for last minute meals because you can thaw the already cooked meat in the microwave while you’re setting the water to boil for the pasta and making a bit of garlic bread.
If you don’t have a jar of sauce around, heat up as much tomato sauce as you need and add some Italian herbs, garlic, sugar, and a bit of red wine. Simmer.
Or heat up a can or two of pureed tomatoes and do the same for a thicker sauce.