1/4 cup gochujang Korean chili paste
3 cloves garlic
1-inch fresh ginger
2 tablespoons sugar
2 tablespoons rice wine vinegar
2 tablespoons soy sauce
1 teaspoon coarse ground black pepper
1/2 cup neutral oil
3 scallions, chopped
2 tablespoons cilantro
2 pounds flank steak or skirt steak
Cucumber, sliced thin
In a food processor, combine the gochujang, garlic, ginger, sugar, vinegar, soy sauce, black pepper, oil, scallions, and cilantro. Pulse a few times until the marinade is combined and forms a very smooth sauce.
Pour about 1/2 cup of the marinade into a separate container and refrigerate it for later. Put the steak in a shallow dish, and pour the rest of your marinade over the steak. Make sure the marinade covers the entire surface of the steak, top and bottom. Let it marinate in the fridge overnight.
When you're ready to cook, preheat your grill to medium-high heat. Grill the steak for 6 to 8 minutes per side, depending on thickness, until the steak is cooked medium-rare. It should reach an internal temperature of 130 to 135°F. in the thickest part of the steak.
Remove the steak from the grill, tent it with foil, and let it rest for 3 to 4 minutes.
Slice the steak into thin pieces across the grain and serve over cooked rice. Garnish with kimchi, fresh cucumbers, cilantro, and a drizzle of reserved sauce.