Stir 4 minced garlic cloves, 1 teaspoon minced peeled ginger, 3 tablespoons soy sauce, 2 tablespoons granulated sugar, 2 tablespoons water, 2 teaspoons gochujang, and ¼ teaspoon black pepper together in a small bowl.
Heat 1 tablespoon neutral oil in a large 12-inch skillet over medium-high heat until shimmering.
Add 1 pound lean ground beef and cook, breaking up the meat into small pieces, until browned, about 6 minutes.
Stir in the sauce and cook until it evenly coats the beef, about 1 minute.
Turn off the heat. Stir in 1 tablespoon toasted sesame seeds and 1 teaspoon toasted sesame oil.
Divide 4 cups hot cooked white rice between 4 bowls.
Divide the beef over the rice.
Divide ½ thinly sliced medium English cucumber, 1 peeled and shredded medium carrot, ¼ shredded small red cabbage, and 1 thinly sliced medium scallion between the bowls.
