Pan-Seared Beef with Scallion Sauce

10 oz chuck beef short ribs well-marbled, thinly sliced to ⅛ inch, 3 mm thick. Or use well-marbled steak and cut into strips
4-5 stalks green onion
2 large cloves garlic
½ tsp salt
¼ tsp black pepper
½ tbsp toasted sesame seeds more for garlish
1 tbsp mirin or 1/2 tsp sugar
1½ tbsp sesame oil
1 tbsp butter optional, if you want to make a sauce
1 egg yolk optional, for serving with rice

Slice a well-marbled cut of steak or boneless short rib into thin pieces around 1/8inch, 3mm or cut into strips.
In a bowl, mix together chopped green onion, minced garlic, salt, black pepper, sesame seeds, mirin, and a splash of sesame oil.
Layer the mixture over your beef and let it sit for about 10 minutes. No need for a long marinade, just enough to soak in the flavor.
Heat a pan over medium heat (if the beef is well-marbled, no extra oil needed). Pan-fry the beef slices for about 1 minute per side, or until the seared side just becomes golden brown. If your pieces are thicker, give them a bit more time.
If serving with rice, add 1 tbsp butter and 1/4 cup water to deglaze the pan. Scrape up the flavorful bits and simmer for a minute to create a quick scallion sauce.
Layer the beef over the rice, drizzle with the sauce, and if you’re feeling extra indulgent, top it with an egg yolk. Enjoy with a hot bowl of rice or on its own!