01 - Toast the bread slices in a toaster or on a grill pan until golden and crisp to your preferred level of doneness.
02 - Halve the avocado, remove the pit, and scoop the flesh into a small bowl. Add lime juice, salt, and pepper, then mash with a fork until nearly smooth.
03 - Divide the mashed avocado evenly and spread it across each toasted bread slice, covering the surface to the edges.
04 - Top each slice with an equal portion of the chopped kimchi, scattering it over the avocado layer.
05 - Sprinkle with toasted sesame seeds and chopped green onions. Add red pepper flakes or a light drizzle of sesame oil if desired. Serve immediately.