In a small bowl, whisk together 1 tbsp (15 mL) of the vinegar and the white sugar until dissolved. Add sliced cucumber and toss to coat. Set aside to marinate.

In a large bowl, whisk together remaining vinegar, soy sauce, Gochujang, 1 tbsp (15 mL) of the sesame oil, brown sugar and garlic. Add sliced steak and toss to coat. Set aside to marinate.

Heat 1 tbsp (15 mL) of the sesame oil in a large skillet over medium-high heat. Add baby bok choy and carrots; sauté until softened, about 2-3 minutes; remove from pan. Add remaining sesame oil and shiitake mushrooms; sauté until softened, about 2-3 minutes; remove from pan. Add bean sprouts; sauté until softened, about 1-2 minutes; remove from pan. Set vegetables aside.

In the same skillet over medium-high heat, add the marinated steak and sauce. Cook 4-6 minutes or until steak is cooked through and liquid has evaporated.

While the steak cooks, prepare the fried egg. In a large skillet over medium heat, melt butter. Crack 2 eggs into skillet. Let eggs cook until whites begin to turn opaque, about 3 minutes. Gently flip eggs and cook for 1 minute. Remove from pan.

To serve, divide the cooked rice between two large bowls. Top each with steak, vegetables, quick-pickled cucumbers, fried egg and desired garnishes.