Putt he tomatoes in boiling water, cook for a short time, take them out and peel them.
Finely chop the shallots, garlic and tomatoes.
Heat oil in a pan and shortly fry the shallots and the garlic, add white wine and thyme and cook until its half reduced.
Put the blue mussels in the pan, cover it and let it simmer for 8 minutes.
Remove ¾ of the liquid, add the tomatoes and let simmer uncovered for 5 minutes.
Taste the sauce and eventually season it with salt and pepper and cover with chopped parsley.