2 slices bread, either soft sandwich bread or large rustic slices, not more than 1/2-inch thick
1 tablespoon mayonnaise
1/2cup grated mozzarella, Cheddar or other mild, semifirm cheese
1/4cup drained and coarsely chopped kimchi
Instructions
Heat a heavy skillet over medium-low heat. Thinly spread 1 side of each slice of bread with 1/2 tablespoon mayonnaise. Place the bread, mayonnaise-side-down, in the skillet and divide the mozzarella evenly over the slices.
When the cheese has just melted (no individual shreds of cheese remain), 6 to 10 minutes, add the kimchi to one side. Use a spatula to top with the other slice of bread, cheese-side-down. Press with the spatula to meld, then let cook, covered, flipping as needed to prevent burning, until the bread is crusty-brown and the sandwich is warmed through, 2 to 4 minutes.