Place some oil into a frying pan. Once the oil is hot, add-in the marinated bulgogi beef. Use your chopsticks to separate each beef piece - so it doesn't clump together.
Then use a pair of kitchen scissors to cut any large slices in half - makes it easier to eat later.
The bulgogi - as it cooks - will release lot of juice. Tilt the pan to one side - so the juices can pool-up to one side. Then move the frying pan slightly to one side - so you can focus the flame (or heat source) directly under the juices. Let most of the juice sizzle away - until you see large-sized bubbles (reference video).
Then add in the marinated rice cakes. Followed by the stir-fried carrots, onions and mushrooms. Followed by the diced spring onions.
Stir-fry for 1 minute. Turn off heat - top-off with a few shakes of sesame seeds.
Serve with a bowl of hot rice. And a side of Jalapenos or Kimchi!