1. Bring a large amount of salted water to a boil. Cook the penne for 8 minutes (al dente). Drain and rinse under a stream of cold water. Scrub and rinse the mussels several times. Discard any that remain open. Peel and chop the garlic and shallot. Rinse and dry the cherry tomatoes.
2. In a non-stick wok, pour the white wine, add the garlic and shallot, then bring to a boil. Add the mussels, cook for 4 minutes over medium heat until they open: cover halfway through cooking. Remove the mussels from the shells. Strain the cooking juice through a sieve, pour it into a pitcher with the cream and mix.
3. Wipe the wok, melt the margarine in it. Add the cherry tomatoes, cook for 2 minutes over medium heat. Add salt. Add the pasta, cook for 1 more minute. Pour in the creamy cooking juice, continue cooking for 2 minutes while stirring: add the mussels and basil at the last moment. Give it three turns of the pepper mill and serve.