Make a fire on one side of a charcoal grill. When the fire is hot, prick the eggplants all over with a fork, and place them on the hot side of the grill for 10 minutes, turning occasionally, to char the skin all over. Move the eggplants to the cool side of the grill, put on the lid, making sure the vents are open, and roast the eggplants for 40 to 45 minutes, until they collapse when you press on them, turning once halfway through. Transfer the eggplants to a platter and cut in half lengthwise, allowing any liquid to run out.
With a slotted spoon, scoop the insides of the eggplants into the bowl of a food processor fitted with the steel blade, discarding the skin and any excess liquid. Add the yogurt, lemon juice, mint, garlic, 1 tablespoon olive oil, the Sriracha, 2 teaspoons salt, and 1 teaspoon pepper. Pulse just five or six times to combine but not puree the ingredients. Taste for seasonings; it should be highly seasoned!
Transfer to a shallow serving bowl, drizzle with olive oil, sprinkle with extra mint and salt, and serve warm or at room temperature with pita triangles.