Cook your spaghetti or pasta of choice and be sure to reserve 1/2 cup of the starchy pasta water.
Combine all of the ingredients: In a large bowl, gently mix together all of the ingredients for the meatballs: ground beef, breadcrumbs, egg, onions, ketchup, Dijon, garlic, oregano, garlic powder, parsley, salt, and Worcestershire. Work the meat just until combined either with clean hands or a spatula or spoon.
Form into meatballs: I like to have a rimmed baking sheet by my side so I can place the rolled meatballs onto it. Either using your hands or a cookie scoop, scoop out some of the meat mixture and roll into a ball ~2-3 Tbsp. each. Continue shaping until all meat is used and place on the baking sheet, not touching. You will have about ~17-18 meatballs.
Cook the meatballs: In a large frying pan over medium heat, warm 1-2 Tbsp. olive oil. Place meatballs down in an even layer and cook on each side for 3-5 minutes or until they are browned on each side.
Simmer meatballs: Pour the red sauce and the 1/2 cup reserved pasta over the meatballs, bring to a simmer. Turn the heat down to low and cover with a lid. Allow to simmer for 15-20 minutes. The longer they simmer the more tender they become!
Serve meatballs over cooked spaghetti noodles and garnish with cheese and Italian parsley.