1. Wash and clean the mussels under cold running water.
2. For more instructions on how to clean the mussels, visit this page.
3. Bring 3 litres of water, with 1 tablespoon of salt in it, to a boil and cook the penne according to package instructions.
4. In the meantime, heat the extra virgin olive oil in a large heavy pan, and saute the chopped onion and garlic for 2-3 minutes.
5. Add the mussels and the sliced banana pepper, and saute until all the mussels are open.
6. Discard any mussels that fail to open.
7. Deglaze with the white wine, and add the lemon juice, parsley and basil.
8. Season to taste with sea salt and freshly ground black pepper.
9. When most of the white wine has evaporated, stir in the butter.
10. Strain the boiled penne and return it to the saucepan.
11. Add the sauce with the mussels to the penne and stir well.
12. Turn the heat back on briefly and stir well, until all the penne is coated with the sauce.
13. Remove the saucepan from the heat and serve.
Tip: If you don't have a large enough pan that can hold 2 pound of mussels, you can use two separate pans at the same time.