Clean and deseed the bell pepper. Then with a teaspoon carefully remove the inside of the zucchini. Drizzle the emptied vegetables with a little olive oil and a good sprinkle of pepper and salt.
Peel, clean and trim the onion, garlic cloves, carrot and celery stalk. Then dice all of them up finely and add them all to a clean blender. Blend until you get a fine vegetable paste.
Stuff the meatballs into the cleaned vegetables and cover with the tops.
Then transfer the stuffed vegetables to a baking dish and drizzle with extra olive oil. Bake the vegetables in a preheated oven at 356°F (180C°) for 45 minutes covered by a sheet of tinfoil. Then remove the tinfoil and bake the vegetables for another 15 minutes. Then remove them and serve hot.