Add extra chili peppers for more heat!
Preheat the oven to 180°C. Wash the mussels and remove any broken ones.
Take four large sheets of aluminum foil. When you fold them later, there should still be enough space between the shells and the top to allow the steam to circulate properly. Fold the foil in half and place a sheet of parchment paper of the same size in the center of each foil.
Fold the edges of the foil slightly upwards so that the liquid doesn't spill out when you fill the packet.
Distribute the mussels, white wine, fish stock, parsley, chili pepper, tomatoes, and a generous drizzle of olive oil over the parchment paper sheets. Season the filling with pepper. You can also add some salt, but keep in mind that the liquid released from the shells will already be quite salty.
Make sure not to stack the mussels on top of each other, as they will have a harder time opening.
Fold the foil sheets closed over the filling and fold the edges over about 1 cm to ensure the packets are well sealed. Again, make sure there is enough space inside for the steam to circulate. Place the packets on a baking sheet in the preheated oven for 10-15 minutes. Check if the mussels are ready by slightly opening the packet. If the shells are open, the dish is ready.
Open the packets before serving and garnish the filling with a few basil leaves.
