Warm the honey and crushed red pepper flakes in a small saucepan over low heat for 3-4 minutes, until the honey smells fragrant and the flakes darken slightly. Remove from the heat and keep warm.
Crumble the feta into the bowl of a food processor. Add the Greek yogurt, olive oil, lemon juice, garlic and black pepper.
Process for 2-3 minutes, scraping down the sides once or twice, until the dip is completely smooth, creamy and a little fluffy.
Spoon the whipped feta into a shallow serving bowl and swirl the top with the back of a spoon.
Drizzle the warm chili honey over the dip and scatter the pistachios on top.
Serve right away with pita chips and carrot sticks, with extra honey on the side.
