01 - Toast the bread slices to your preferred level of crispness using a toaster or grill pan.
02 - Halve the avocado, remove the pit, and scoop the flesh into a small bowl. Add lime juice, salt, and pepper; mash until nearly smooth with a fork or spoon.
03 - Spread the mashed avocado evenly over each toasted bread slice.
04 - Top each slice with an equal portion of chopped kimchi.
05 - Sprinkle with toasted sesame seeds and green onions. Add red pepper flakes or a drizzle of sesame oil if desired. Serve immediately.