Classic Italian Meatballs

Name: Classic Italian Meatballs
Prep time: 30 min
Total time: 30 min
Cuisine: European, Italian, Mediterranean
Ingredients: 1 c. fresh bread crumbs; 1/2 c. whole milk; 1 lb. ground beef; 1/2 lb. ground pork; 1/2 lb. Italian sausage, casings removed; 1 small yellow onion, finely chopped; 3 cloves garlic, finely chopped; Kosher salt; Freshly ground black pepper; 2 large eggs, beaten to blend; 1 c. finely grated Parmesan, plus more for serving; 1/4 c. chopped fresh parsley, plus more for serving; 2 tbsp. extra-virgin olive oil; 1 (32-oz.) jar or homemade marinara sauce