Step 1: Prepare the Bread Crumb Mixture: In a medium bowl, combine the 4C bread crumbs with the milk. Allow the mixture to sit for about 5 minutes, so the bread crumbs can absorb the milk and soften. This step ensures the meatballs are tender and moist.
Step 2: Combine the Ingredients: In a large bowl, gently combine the ground beef, ground pork, soaked bread crumbs, Parmesan cheese, parsley, minced garlic, egg, salt, and pepper. Mix with your hands or a wooden spoon until just combined. Avoid overmixing, as this can make the meatballs tough.
Step 3: Form the Meatballs: Roll the meat mixture into 1 1/2-inch meatballs. Aim for uniform size to ensure even cooking.
Step 4: Brown the Meatballs: Heat the olive oil in a large skillet over medium heat. Carefully place the meatballs in the skillet, ensuring not to overcrowd the pan. Brown the meatballs on all sides until they are nicely seared. This step adds depth of flavor and helps to keep the meatballs intact during simmering. Work in batches if necessary.
Step 5: Simmer in Sauce: Pour the marinara sauce over the browned meatballs in the skillet. Bring the sauce to a simmer, then reduce the heat to low, cover the skillet, and cook for at least 30 minutes, or up to an hour, allowing the meatballs to fully cook and the flavors to meld. Stir occasionally to prevent sticking.
Step 6: Serve: Serve the meatballs hot over your favorite pasta, in a sandwich, or as an appetizer. Garnish with fresh parsley and extra Parmesan cheese, if desired.
For a spicier version, add a pinch of red pepper flakes to the meat mixture or the sauce. Ground turkey or chicken can be substituted for the ground beef or pork. For gluten-free option, consider using gluten free bread crumbs.