Pour flour onto a work surface. Press a depression in the middle. Add eggs, olive oil and salt and knead everything into a smooth pasta dough. If the dough is too dry, add 1 tablespoon of water if necessary.
Wrap the pasta dough in foil and let it rest for 30-40 minutes. Meanwhile, for the sauce, drain the mussel meat on a sieve. Peel and chop the onion and fry it in hot fat in a pot until it becomes glassy.
Briefly braise the mussel meat with it. Add chunky tomatoes, bring to the boil and simmer for 2-3 minutes. Season to taste with salt and pepper, set aside. For the ravioli filling, wash and clean the zucchini and dice very finely.
Peel and chop the onion. Peel garlic and crush finely. Crumble the ricotta. Wash parsley and thyme and dab dry. Chop the parsley finely and remove the thyme leaves.
Heat the oil in a frying pan and fry the garlic and onions until transparent. Add zucchini and thyme, except for 1 tablespoon, and braise for 4-5 minutes. Fold in parsley and cheese, season and let cool off.
In the meantime roll out the pasta dough very thinly (preferably with a pasta machine). Spread 1 tablespoon of the filling on each half of the pasta dough at a distance of about 10 cm. Spread the dough around the piles with egg white and fold the other half of the dough over it.
Press the dough well between the heaps. Cut out squares of 10x10 cm with a dough wheel (16-20 pieces). Cook the ravioli in plenty of boiling salted water for about 5 minutes. Heat the tomato sauce again and arrange on plates with the ravioli.
Serve sprinkled with remaining thyme.