For the meatballs:
1) Place the minced meats, breadcrumbs, parsley, Parmesan, salt, pepper, nutmeg, egg and 180ml of warm water in a bowl and combine very lightly with a fork. Using your hands, lightly form the mixture into 4cm meatballs. You will have 14 to 16 meatballs.
2) Pour equal amounts of vegetable oil and olive oil into a large frying pan to a depth of 1cm and heat. Very carefully, in batches, place the meatballs in the hot oil and brown them well on all sides over a medium-low heat, turning carefully with a spatula or a fork, about 10 minutes for each batch. Don't crowd the meatballs. Remove cooked meatballs to a plate covered with paper towels. Discard the oil but don't clean the pan.
For the spaghetti sauce:
1) Heat the olive oil in the same pan. Add the onion and saute over medium heat until translucent, 5 to 10 minutes. Add the garlic and cook for 1 more minute.
2) Add the wine and cook on a high heat, scraping up all the brown bits in the pan, until almost all the liquid evaporates, about 3 minutes. Stir in the tomatoes, parsley, salt and pepper.
3) Return the meatballs to the sauce, cover, and simmer on the lowest heat for 25 to 30 minutes, until the meatballs are cooked through.
For the spaghetti:
1) Cook the spaghetti in boiling, salted water according to the package instructions.
2) Serve the meatballs hot on the cooked spaghetti and pass the grated Parmesan for garnish.