½ lb. Pappardelle's Spicy Garlic Tagliatelle
4 tbsp. oyster sauce (or fish sauce)
3 tbsp. butter, divided
1 tbsp. soy sauce
3 tbsp. brown sugar
1 tbsp. toasted sesame oil
¾ lb. flank steak, thinly sliced
4 cloves garlic, minced
½ lb. broccoli florets
4 green onion stalks, sliced
Crushed red pepper flakes, to taste