Boil chillies, water, sugar, mirin, and lime juice in a saucepan.
Cook for 8 minutes while stirring, then cool to thicken.
Grill lamb belly on medium-high for 8 minutes, turning once, then rest for 5 minutes.
Blend lime juice, aromatics, sugar, and fish sauce into a dressing.
Mix sliced chilli, mizuna, mint, coconut, and cucumber in a bowl.
Toss sliced lamb belly into the salad with the prepared dressing.
Heat a griddle pan and season oiled lamb chops.
Griddle chops for 3 minutes per side and rest for 2 minutes.
Serve lamb chops with chilli jam and salad on the side.