Meatballs:
Stir the minced meat with salt until it becomes sticky - use the dough hooks of the electric mixer.
Add all the other ingredients and mix the mince thoroughly. It should be quite firm.
Use a teaspoon or dessert spoon to form small balls and place them on a baking tray lined with baking paper.
Bake the meatballs in the oven at 250 degrees Celsius (482 degrees Fahrenheit) fan for 10 minutes and then for 10 minutes at 200 degrees Celsius (392 degrees Fahrenheit) fan. Turn them once during baking.
Tomato Sauce:
Finely chop the onions and garlic.
Heat olive oil in a pot and sauté the onions and garlic for a couple of minutes.
Add dried oregano and continue cooking.
Add white wine and let it almost evaporate.
Add passata and let the sauce simmer over low heat for at least 30 minutes - preferably longer.
Season the tomato sauce with gastrique, salt, pepper, chili flakes/cayenne pepper, sugar, and lemon juice.
Serving:
Cook the spaghetti according to the package instructions.
Mix the tomato sauce in the spaghetti and arrange it with the meatballs on top.
Garnish with basil leaves and serve the dish with grated Parmesan.