Preheat oven to 400 degrees F / 204 degrees C.
In a large bowl, mix all of the meatball ingredients and knead with hands until well-combined.
½ cup onion, 3 cloves garlic, 1½ pounds ground pork, 7 button mushrooms, 1 teaspoon sage, 1 teaspoon Himalayan salt, 1 teaspoon black pepper, 1 teaspoon fresh basil, ¼ cup almond flour, 3½ ounces mozzarella cheese
With your hands carefully form a big meatball, and throw it from one hand to another a couple of times to release the air. Once formed, place in an ovenproof dish. Repeat with remaining meatballs.
Once all meatballs are in the ovenproof dish, bake for 20 minutes. (Do not turn off oven.)
In a medium saucepan, combine all tomato sauce ingredients except mozzarella cheese and simmer on medium heat for 10 minutes. The sauce should be pretty thick so make sure that it has considerably simmered down to thicken it.
1 pound crushed tomatoes, 1 teaspoon oregano, 1 teaspoon fresh basil, ½ teaspoon black pepper, ½ teaspoon Himalayan salt, ¼ teaspoon garlic powder, ¼ teaspoon onion powder
Once the meatballs have cooked for 20 minutes, take the dish out of the oven, cover the meatballs with the tomato sauce, and top with mozzarella cheese. Place in the oven again and bake for an additional 10 minutes (or until the mozzarella has a nice golden-brown crust).
3½ ounces mozzarella cheese
Take out of the oven and serve hot.