In a large mixing bowl, combine the ground venison and ground pork (if using).
Add the breadcrumbs, Parmesan cheese, parsley, garlic, onion, egg, milk, salt, pepper, oregano, basil, and red pepper flakes.
Using your hands, gently mix all ingredients until just combined. Avoid overmixing, as this can make the meatballs tough.
Preheat your oven to 400°F (200°C) if you plan to bake the meatballs. Line a baking sheet with parchment paper.
With damp hands, roll the mixture into 1- to 1.5-inch meatballs. Place them on the baking sheet, leaving space between each meatball.
Cook the Meatballs with Baking:Bake the meatballs in the preheated oven for 15-20 minutes or until browned and cooked through. Cook with Pan-Frying:Heat a large skillet over medium heat and add a few tablespoons of olive oil. Once the oil is hot, add the meatballs in batches, browning them on all sides (about 10-12 minutes).
Transfer the meatballs to a paper towel-lined plate to remove any excess oil.