Preheat oven to 400ºF.In a medium-sized mixing bowl, add all of the ingredients for the meatballs and mix together with your hands. Don't over work the meat. Roll into smaller than usual meatballs, around 1-inch, or so.Heat 2 tablespoons of olive oil or ghee in a large, heavy-bottomed, oven-safe skillet over medium heat (I like to use one pan for the whole recipe, so I opt for my cast iron). Working in batches and adding more oil as necessary, cook the meatballs until browned on all sides, about 5 to 7 minutes. They don't need to be cooked through, as they will continue to cook in the frittata. Set the cooked meatballs aside.In a medium bowl, whisk the eggs with a small pinch of salt, red pepper flakes and basil. Set aside.If there is still oil in the pan from the meatballs, no need to add more, if there isn't add more olive oil or ghee, as needed. Still over a medium heat, add the onion and mushrooms sauté about 6-8 minutes until the onion is translucent and the mushrooms softened. Add the garlic and sauté another 2 minutes, being careful not to burn it.Add the zucchini noodles and cook them quickly, tossing around in the pan to mix with the other ingredients, give them just a minute or two. Pour the eggs over the veggies and give it all a really quick stir to combine. Add the meatballs back in, I like to strategically place them throughout, so everyone will get some. Cook over a medium-low heat for about 5 minutes or until the eggs are just set and there isn’t a lot of liquid running around the pan. To do this, run a spatula underneath the sides of the frittata and tilt the pan so the uncooked eggs run to the underside and cook.Place the skillet in the center of your preheated oven. Allow to bake for 13-15 minutes, until it is golden brown, well set and puffy, be sure when you stick a knife through the center of the frittata, it comes out clean.Remove from oven with oven mitts and let cool for several minutes, cut into wedges and serve, topped with warmed marinara, fresh basil, red pepper flakes and grated cheese, if you like.