To blister grapes, toss them in olive oil and a pinch of salt. If using an air fryer preheat to 350 and cook grapes for 7 mins on parchment paper. If using the oven, preheat to 350. Then place grapes on parchment lined baking sheet and cook for 10 mins or until blistered.
Lay out flatbread on a baking sheet. Drizzle olive oil, fresh rosemary, black pepper and blue cheese crumbles on top. Once grapes have been cooked add them on top. Cook flatbread in the oven at 350 for 5-10 mins, until cheese is bubbly and crust is golden brown.
Remove flatbread and drizzle with balsamic reduction. Slice, serve, and enjoy!