Mussels saganaki with mustard and feta cheese

Sauté the onions slightly over moderate heat. Towards the end of sautéing add the garlic and continue for half a minute then stir in the wine. 

Before the wine boils add the mustard and dissolve it. Then let it boil for four or five minutes until the alcohol evaporates.

Add the mussels and let everything simmer until the sauce starts to thicken at which point add the feta cheese that you have already crumbled by hand and wait for it to melt.

When the feta cheese melts add the parsley and serve.