Place dish in fridge to thaw overnight or for 24 hours.
Heat a large frying pan over medium heat. Add 2 Tbsp of neutral oil and heat until oil is hot and glistening.
Add in just the beef (gently spreading the meat out across the pan). Sauté for 2-3 minutes, stirring occasionally.
Add greens and 1-2 Tbsp of water to the pan. Toss and cover with lid for 3-5 minutes.
Remove from heat and serve over steamed rice.
Garnish with thinly sliced scallions and sesame seeds. Serve with Kewpie Potato Salad.
FOR STIR FRY: Alternatively, you can use the beef and greens to make a noodle stir fry. To do so, add cooked noodles after Step 4 and toss to combine (you can add 1 Tbsp of additional soy sauce if desired). Cook for 1-2 minutes longer, then serve. Garnish with scallions and sesame seeds.