2 tbsp authentic French Dijon mustard
2 lbs bone-in skin-on chicken thighs, patted bone dry
2 tbsp extra virgin olive oil
2 tbsp unsalted butter
2 medium shallots, finely minced
Kosher salt and freshly cracked black pepper to taste
Fresh herbs or chopped parsley for garnish
Lemon wedges or sliced scallions for serving