Slow Cooker Bulgogi

Whisk 1/4 cup soy sauce, 2 tablespoons sugar, 2 teaspoons sesame oil, 1 clove garlic, and 1/2 teaspoon black pepper together in a large bowl; stir in beef. Cover with plastic wrap and let marinate in the refrigerator, at least 30 minutes and preferably overnight.

Combine remaining 1/4 cup soy sauce, 2 tablespoons sugar, 2 teaspoons sesame oil, 1 clove garlic, and 1/2 teaspoon black pepper in a small bowl to make a second batch of marinade.

Toast sesame seeds in a small skillet over medium heat until lightly browned, 3 to 5 minutes.

Place marinated beef, second batch of marinade, toasted sesame seeds, and green onion in a slow cooker. Cook on Low until beef is tender and flavors are combined, 6 to 8 hours.