Preheat skillet.
Cover bottom of skillet with olive oil.
Generously salt chicken on both sides.
Place each chicken thigh, skin down on hot skillet.
Leave chicken untouched for about 15 minutes.
Halfway through searing, place cut onions around the chicken and sprinkle with some hot pepper flakes or black pepper.
Once 15 minutes are up, flip each chicken thigh. The skin needs to be a nice golden brown color.
Continue browning on the other side for an additional 15-20 minutes or until the internal temperature of the chicken reaches about 160°F.
Add the wine half way through cooking and allow it to "sfumare", evaporate or cook out.
Now crack the egg in a bowl and add the juice of one lemon and the mustard. Mix well. You can also replace the egg with two egg yolks only, without the egg whites.
Pour the egg, mustard and lemon sauce over the chicken and immediately remove the pan from the heat source. The egg will continue cooking with the heat of the chicken and pan.
Top everything off with the chopped parsley and serve immediately.
Serve it with either a salad or a green vegetable and some delicious potatoes.
