Wash the mussels and brush the shells, or use a knife, to remove the silt and rock debris that may be stuck. Remove the "beards" by pulling them out. Discard any mussels with cracked shells. If some mussels are open, tap them gently against the counter. If they don’t close discard them too. Set aside.
In a saucepan, heat the olive oil and sauté the onion, garlic cloves and bay leaf. Add the white wine and let simmer over medium heat for 2 minutes, until the alcohol evaporates and the sauce reduces. Add the peeled tomatoes slightly mashed and season with salt and chili powder. Simmer for 10 minutes.
Add the mussels and cook over high heat for 4-5 minutes with the lid on, shaking the pan from time to time so it doesn’t stick to the bottom. Do not overcook, because mussels will become hard.
Sprinkle with chopped coriander and serve with slices of bread or fries.