Dice the celery, peel, seed and cut the tomatoes into eighths, halve the shallots.
Wash the mussels and boil them in 0.25 liters of white wine for 3 minutes, then put them in a sieve and collect the broth. Now remove about 2/3 of the mussels from their shells. Next, sauté the vegetables in a little olive oil, then add the mussel broth and 100 ml of cream and steam everything for 10 minutes.
Add the mussel meat and season everything (with pepper and a little salt). At the same time, cook the spaghetti and add the finely chopped zucchini strips for the last 3 minutes.
Finally, drain the spaghetti, dress with the clam sauce and garnish with the remaining clams.
