1Slice cucumbers thinly and toss with 1 tbsp rice wine vinegar, 1 tsp sesame oil, ½ tsp sugar, a pinch of salt, 1 tsp red pepper flakes (optional), and 1 tsp toasted sesame seeds.
2In a hot pan, prepare the sauce by adding ⅓ cup soy sauce, 3 tbsp gochujang, 3 tbsp brown sugar replacement, ¼ cup beef broth, 1 tbsp rice wine vinegar, 6 minced garlic cloves, 1 ½ tbsp grated ginger, and 1 tbsp cornstarch mixed in equal parts cold water.
3Coat sliced beef with 2 tbsp cornstarch, ½ tsp salt, and pepper to taste.
4Sear the beef in a hot wok for 45 seconds on one side and 30 seconds on the other, working in batches.
5Toss the cooked beef with the prepared sauce for 30-45 seconds.
6Serve the beef over rice with the cucumber salad and garnish with green onions and sesame seeds.