Step 1

Adjust oven rack to upper-middle position and preheat oven to 475 degrees.

Step 2

Heat olive oil in a large skillet, over medium-high heat, until shimmering. Cook onions until golden and very soft, 10-15 minutes.

Step 3

Add garlic, Italian seasoning, and pepper flakes and cook until fragrant, about 1 minute. Set aside and cool.

Step 4

In a large mixing bowl, add milk and bread and allow to sit for 10 minutes. Mash.

Step 5

Add cooled onion mixture, ground beef, sausage, Parmesan, eggs, salt and pepper and knead until ingredients are well combined.

Step 6

Form mixture into 2 1/2 inch meatballs (you should have approximately 16 meatballs), place on rimmed baking sheet and bake for about 20 minutes, or until well browned.

Step 7

Transfer meatballs to pot of sauce and simmer for 15-20 minutes. Serve over cooked pasta and garnish with fresh chopped basil or parsley!