Heat a grill to medium-high heat. Cut nectarines in half and remove the pits. Drizzle with a bit of oil and grill until charred and warmed through, about 3 minutes per side. Transfer the nectarines to a serving platter, drizzle with honey, and sprinkle with the crumbled gorgonzola and mint leaves. Roughly chop the toasted hazelnuts and sprinkle them over the platter, along with a bit of flaky salt. Eat with a fork and knife.