Brush the mussels thoroughly under water. Sort out damaged and open mussels and discard. Put the mussels in a large saucepan with a little water and heat them covered until all the mussel shells have opened.
Drain the mussels and throw away any closed mussels.
In a large saucepan, sauté the chopped onion in oil and add the finely chopped garlic. Now deglaze with red wine, add the tomatoes, oregano and thyme. Now let the sauce boil down over medium heat for about 10 to 20 minutes. Put the mussels in the sauce and let simmer for 10 minutes. Season with salt and pepper and fold in the parsley.