Grate the zucchini using a grater with large holes.
Mix the grated zucchini, fresh ricotta, grated parmesan, beaten eggs, salt, pepper, breadcrumbs, finely-chopped sage leaves and chopped parsley in a large bowl until the mixture is well-combined and smooth.
Make the vegetable fritters. Place them on a plate covered in baking paper and put in the freezer for 10-15 minutes.
Sauté the chopped onion and chili pepper in extra virgin olive oil in a skillet until golden. Puree the San Marzano DOP tomatoes in a blender and add to the skillet.
Cook for about 20 minutes adding a little water if needed.
In the meantime, heat the sunflower oil and fry the zucchini and ricotta fritters, when golden and crispy, drain well on kitchen paper.
Serve the fritters on the tomato sauce, garnished with fresh basil.