Peel and finely chop the onion. Knead minced meat, diced onion and egg yolk. Season with salt and pepper. Form approx. 12 balls from the minced dough. Clean the celery and put some green aside. Wash the sticks and cut them into fine slices.
Peel the garlic and press it through a garlic press. Cook spaghetti in boiling salted water for about 8 minutes. Heat the oil in a pan. Fry meatballs in it all around for about 5 minutes. Add garlic and fry in it. Deglaze with 100 ml water and chunky tomatoes, bring to the boil. Stir in stock. Add bay leaf and simmer for about 5 minutes. Wash, clean, seed and finely dice the tomatoes. Slice parmesan. Remove the bay leaf from the sauce.
Deglaze with 100 ml water and chunky tomatoes, bring to the boil. Stir in stock. Add bay leaf and simmer for about 5 minutes. Wash, clean, seed and finely dice the tomatoes. Slice parmesan. Remove the bay leaf from the sauce. Season sauce with sugar, salt and pepper. Drain the pasta and let it drain. Arrange on plates with the tomato sauce and the meatballs. Sprinkle with parmesan slices and tomato cubes. Garnish with remaining celery green
Season sauce with sugar, salt and pepper. Drain the pasta and let it drain. Arrange on plates with the tomato sauce and the meatballs. Sprinkle with parmesan slices and tomato cubes. Garnish with remaining celery green