Pan-Seared Steak in Butter Sauce

(450g) flank steak, cut into strips

+2 tablespoons unsalted butter, divided

small shallot, finely chopped

garlic cloves, minced

red chili pepper flakes, to taste

Dijon mustard

minced fresh thyme

finely minced chives

beef stock (or water)

lemon juice

Salt and fresh cracked pepper,

Fresh chopped parsley, for garnish