In a large bowl add your ground beef or ground bison, flour, Worcestershire, parsley, parmesan, sea salt, pepper, dried basil and the egg.
Stir to combine, then form the meat mixture into small (around 1-1/2-inch diameter) meatballs. I like to use a cookie scoop for this.
Heat a large skillet over medium heat and drizzle with a tiny bit of avocado or olive oil. Sear the meatballs just until they start to become golden brown, just a couple minutes.
Meanwhile, in your crockpot, stir in the crushed tomatoes or marinara with garlic, onion, and butter.
Transfer your meatballs, in a single layer, into the crockpot and gently stir with sauce.
Cover your crockpot and cook on LOW for 4-5 hours or on HIGH for 2-2 1/2 hours. (I prefer the results of using LOW setting).
Garnish with additional shredded parmesan and fresh parsley if desired and enjoy!