Cut the halloumi into bite-sized cubes and pat them dry with a paper towel.
Warm the olive oil in a skillet over medium-high heat. Add the halloumi and cook for 1 to 2 minutes on each side, until deeply golden.
Meanwhile, gently warm the honey and red pepper flakes in a small saucepan or microwave. Stir in the fresh lemon juice.
Transfer the hot halloumi to a serving plate and drizzle over the hot honey.
Finish with finely grated lemon zest, freshly ground black pepper, sumac, and chopped fresh mint. Serve immediately with cocktail picks.
Notes
Halloumi: Pat the cubes dry before frying so they brown well and splatter less. Halloumi becomes firmer as it cools, so serve it straight from the skillet.Heat level: Use 1/4 teaspoon red pepper flakes for gentle heat or 1/2 teaspoon for a spicier finish. The strength of red pepper flakes varies, so taste before adding more.Sumac: This is optional, but its tangy, slightly fruity flavor works well with the honey, lemon, and mint.Make ahead: The hot honey can be mixed ahead and rewarmed gently. Cut and dry the halloumi in advance, but fry it just before serving for the best texture.