Make the meatballs: put the meat, egg, flour, parsley and salt and pepper in a bowl and mix well with your hands. Shape into 1 inch meatballs.
Set your pressure cooker to saute. Once it becomes hot, add the olive oil. Once the oil is hot, add the onion and cook for about four minutes. Add the garlic and cook for one more minutes, stirring so the garlic does not burn.
Add the tomatoes and the paste, and the seasonings. Put the meatballs into the pot, and push them down with a spoon so they are mostly submerged into the sauce.
Place and lock your lid, and make sure the toggle is set to sealing. Set manual/pressure cook to 10 minutes. When the cooking cycle is done, allow for a ten minute natural pressure release and then quick release the rest of the steam.
This marinara and meatballs can be served over spaghetti squash, or zoodles for a low carb meal, or over regular pasta.