We occasionally have grilled cheese sandwiches with cheddar cheese and kimchi at my home, they're a great late night snack. MrLapLap - who has eaten kimchi pizza - prefers kimchi as a toastie filling than as a pizza topping.

The idea of adding tomato sauce to a kimchi cheese toastie is not one that appeals to me, so I have no intention or plans of trying kimchi pizza. A kimchi quesadilla on the other hand....