Preheat the grill to high (450 to 500 degrees) or cast iron skillet (we will be using the cast iron)
Grill jalapeños on oiled grates, uncovered, turning often, until skins are charred, about 8 minutes
Place chiles in a small ziplock plastic bag seal, or place in a small bowl and cover with plastic wrap
Let stand until cool enough to handle
Peel and discard blistered skins; remove stems and seeds
Process jalapeños, cilantro, lime juice, olive oil, basil, and sugar in a blender until smooth, about 45 seconds
Season with salt and set aside
Salad
Toss together okra, avocado oil, salt, and pepper in a medium bowl. Grill okra on oiled grates/cast iron skillet over high, uncovered, turning once or twice, until okra is slightly blistered and just softened, about 5 minutes. Place okra in a large bowl, and set aside
Grill corn on oiled grates over high, uncovered, turning often, until evenly charred, about 15 minutes. Let cool for 10 minutes; cut kernels off cobs, and add to okra in a bowl; stir in tomatoes, cucumber, onion, coriander seeds, and cumin seeds.
Garnish salad with cilantro and sesame seeds, if using. Serve with dressing on the side.