Thinly slice the cucumbers and place them in a mixing bowl. Sprinkle with the kosher salt and let sit for about 10-15 minutes to draw out the moisture.
Drain off the liquid and gently pat the cucumbers dry with a paper towel.
In a small bowl, whisk the soy sauce, rice vinegar, maple syrup, sesame oil, chili paste, white pepper, and sesame seeds. Pour into the cucumber bowl and toss until the cucumbers are evenly coated. Garnish with green onions.
Cook the Beef Bool Kogi
Heat a cast iron skillet over medium-high heat. Working in batches, add the Beef Bool Kogi in a single layer, making sure not to overcrowd the pan. Cook for approximately 3–5 minutes per side, until browned and cooked through. Transfer to a plate and repeat with the remaining beef.
Assemble the Bowls
Divide the freshly cooked rice among serving bowls. Top with the cooked beef and cucumber salad. Garnish with fresh cilantro and sliced green onions.