Step 1: Prepare the Meatballs

1. Mix the Ingredients: In a large mixing bowl, combine the ground beef, ground pork, breadcrumbs, Parmesan cheese, minced garlic, egg, milk, parsley, salt, black pepper, and red pepper flakes. Use your hands or a spatula to gently mix until well combined.
2. Form the Meatballs: Roll the mixture into 1.5-inch meatballs, making about 18 in total. Place them on a baking sheet or plate.
3. Brown the Meatballs: Heat a large skillet over medium-high heat with a drizzle of olive oil. Sear the meatballs in batches, cooking each side for 1-2 minutes until browned. They don’t need to be fully cooked through, as they’ll finish cooking in the sauce. Remove and set aside.

Step 2: Make the Sauce

1. Sauté the Aromatics: In the same skillet, add a bit more olive oil if needed. Sauté the diced onion over medium heat for 3-4 minutes until softened. Add the minced garlic and cook for another minute until fragrant.
2. Deglaze the Pan: Pour in the chicken or vegetable broth, scraping up any browned bits from the bottom of the pan. Let it simmer for 2 minutes to reduce slightly.
3. Build the Sauce: Stir in the crushed tomatoes, heavy cream, Parmesan cheese, dried basil, oregano, and red pepper flakes. Season with salt and pepper to taste. Simmer for 5 minutes, allowing the flavors to meld.

Step 3: Simmer the Meatballs
Return the browned meatballs to the skillet, nestling them into the sauce. Cover and simmer on low heat for 20-25 minutes, occasionally stirring gently to ensure even cooking.

Step 4: Serve and Garnish
Once the meatballs are cooked through, remove the skillet from the heat. Garnish with fresh basil leaves and extra Parmesan cheese. Serve hot with your choice of pasta, crusty bread, or a light salad.