Halve nectarines and remove pits, then whisk olive oil, honey, and lemon juice; brush each half evenly for bright flavor and to prevent sticking during grilling.

Preheat outdoor grill or stovetop grill pan to medium-high (about 375°F–400°F). Let grates heat 5 minutes until hot with faint smoke for perfect char.

Place fruit cut-side down on grates; grill 3–4 minutes until deep golden-brown char forms and flesh begins to caramelize.

Turn halves gently; grill 2–3 more minutes on skin side until tender edges appear and juices bubble into caramelized lines.

In a food processor, pulse pistachios, Greek yogurt, honey, and vanilla until smooth and creamy; chill 5 minutes.

Spoon generous dollops of cold pistachio cream over warm nectarines; drizzle pan juices, then top with toasted pistachio halves and fresh mint.