For those unfamiliar with seeni sambol, a Sri Lankan condiment of spicy-sweet caramelized onions, these cheesy Hawaiian buns are the perfect place to start. In this recipe, chef Sam Fore makes her own DIY version of the relish by cooking red onions with curry leaves, red pepper flakes, and a dash of tamarind concentrate. The tart-sweet-spicy seeni sambol get sandwiched between a flat of plush Hawaiian rolls along with a mixture of shredded cheese, mayonnaise, jalapeño, and shallots. Then the whole thing is wrapped in foil and baked until toasty and melted.