1. Start by draining the kimchi well. I like to place it in a fine mesh sieve and press gently to remove excess liquid—too much moisture can make the sandwich soggy.
2. In a bowl, mix the shredded cheddar and mozzarella cheese together. This combo melts perfectly and gives a great balance of sharpness and creaminess that my family adores.
3. Spread a thin layer of softened butter on one side of each bread slice. This will be the outside of your sandwich and helps create that golden, crispy crust.
4. Optional: Spread a thin layer of mayonnaise on the other side of the bread for extra crispiness and flavor depth. My husband swears by this step, and I have to admit, it’s a game-changer.
5. Place four bread slices butter-side down on your work surface. Evenly distribute the cheese mixture on top of each slice, then sprinkle the chopped kimchi over the cheese. Add green onions if you’re using them for a fresh pop of flavor.
6. Top with the remaining bread slices, buttered side up, to form sandwiches.
7. Heat a large skillet or griddle over medium heat. Place the sandwiches in the pan and cook for about 3-4 minutes on each side, pressing gently with a spatula, until the bread is golden brown and the cheese is melted.
8. Transfer the grilled sandwiches to a cutting board. Let them rest for a minute, then slice each sandwich into small squares—this is where the fun begins, especially with little helpers at home!
9. Sprinkle toasted sesame seeds over the top for a nutty crunch and a lovely visual finish.

One cooking tip I’ve picked up from years in the kitchen is to keep the heat moderate—not too hot or you risk burning the bread before the cheese melts. Patience here rewards you with perfectly gooey, crispy bites every time.