Mix the meatball ingredients together (bar the oil and butter) thoroughly with your hands and shape into balls (I made 24).
Chill for 30 minutes.
Heat the oil and butter in a pan and fry the meatballs to seal all over.
Remove with a slotted spoon and set aside.
In the same pan heat up the remaining oil and gently fry the onion, garlic and celery for 8 minutes without colouring.
Add passata, sugar, lemon juice, salt and pepper.
Cook the spaghetti according to instructions.
Return meatballs to the pan and simmer for 10 minutes until cooked.
Serve on a bed of spaghetti with a sprinkling of parsley and grated parmesan cheese.