Ultimate Spaghetti and Meatballs

½ Pound Ground Beef, Preferably Chuck
½ Pound Ground Veal or Turkey
½ Pound Ground Pork
2 Tablespoons Grated Onion
1 Large Egg
½ Cup Dry Bread Crumbs
Salt and Pepper
2 Tablespoons Olive Oil
1 (28 Ounce) Jar Pasta Sauce
¾ Pound Spaghetti
Grated Parmesan, Optional

1. Combine meats, onion, egg, bread crumbs, salt and pepper in a large bowl.  Mix gently with your hands until well-blended (do not overmix).  Shape mixture into 8 meatballs, about 2 ½ inches in diamter.
2. Warm olive oil in a large skillet over medium-high heat.  Cook meatballs until brown all over, 6 to 8 minutes, turning carefully with tongs.  Remove skillet from heat and carefully pour pasta sauce over meatballs.  Place skillet over medium heat and bring to a simmer.  Cook gently until there is no trace of pink in center of meatballs, about 20 minutes.
3. Cook spaghetti according to package directions.  Drain well and divided among 4 shallow pasta bowls or plates.  Top each portion with 2 meatballs and ladle on sauce.  If desired, top with grated Parmesan.