Lather your (chicken) thighs in yogurt with a pinch of salt and set aside on counter. This will both bring them to room-temp and tenderize them. We're going for 30 minutes on the marinade.
Place a large pan over medium heat and fill with about an inch of oil. We want this to heat up while we're prepping our other things!
Make my KOREAN SASSY-ASS SEOUL SAUCE. Takes just a few minutes.
Grab 3 shallow bowls. Fill one with flour, one with egg, and one with panko + ½ tsp salt, forming an assembly line in that order. Frying batter will always go: dry (flour) -> wet (egg) -> dry (panko).
Line a plate with paper towels and set near frying pan.
Start breading chicken (it's ok to bread and then wait for oil to continue heating!).
With yogurt still intact, plop thigh in flour, working one at a time. Make sure flour is coating every nook and cranny.
Next, plop it in egg, making sure it gets all wet again.
Lastly, plop it in panko and press breadcrumbs down onto chicken to make sure everything sticks. Rest on a plate.
Repeat with other chicken thigh.
To see if oil is ready, dangle a thigh above the surface of the oil. Dip in the littlest tip of the thigh and see if the oil bubbles all around. If it does, it's ready; if not, continue to hold on plate and test again in a couple minutes.
When it's ready, carefully drop in both thighs. Cook until bottom is a deep golden brown, you sexy motherfucker, about 7 minutes. Flip and repeat.
While thighs are cooking, preheat oven to 250°F.
Remove thighs from oil when done and set on paper towel-lined plate. Immediately sprinkle with salt.
Brush my SASSY-ASS SEOUL SAUCE all over each thigh, covering them completely.
Slap a slice of cheese onto each thigh. Remove paper towel from plate and place thighs in the oven until cheese is melted.