01 - Spread unsalted butter evenly on the exterior sides of each slice of sourdough bread.
02 - Place shredded sharp cheddar and finely chopped kimchi between two slices of bread, ensuring the buttered sides face outward.
03 - Heat a skillet over medium heat. Grill the assembled sandwich until the bread is golden brown and the cheddar melts, about 3 to 4 minutes per side.
04 - Transfer the sandwich to a plate and sprinkle gochugaru over the top before serving.