In a bowl, cut up the kimchi into small bite size pieces using scissors.

In high heat with a little bit of oil, saute the kimchi until the juice has reduced.

Put sugar and drizzle some sesame oil and continue sauteing until nicely caramelized. Set aside.

Using your marinated beef bulgogi or any leftover bulgogi you have, saute it in a pan with a little bit of oil then sprinkle in some sesame seeds.

Cut up the bulgogi into small bitesize pieces and set aside.

In your grilling pan, melt some butter and place slices of bread on top of it. Swirl the bread around until it has soaked up all the butter and the facing down side of the bread is well coated.

On the unbuttered side, put mozzarella cheese on both slices then put kimchi or bulgogi on top of one slice.

Put the breads together to make a sandwich and in low heat, slowly toast its two sides. Flip as needed to prevent the sandwich from burning. Toast until the cheese is melty.