1 pound baby squid, bodies and tentacles separated but left whole
1/4 cup extra-virgin olive oil
1 teaspoon finely grated orange zest
1/2 teaspoon crushed red pepper
1/3 cup chopped tarragon
1/3 cup chopped mint
1 small seedless watermelon (about 3 1/2 pounds)halved, rind removed, flesh
sliced 1/2 inch thick
Ground sumac, for sprinkling (optional, see Note)
In a bowl, whisk the rice vinegar, Champagne vinegar, scallions, jalapeños, 2 teaspoons of the lime zest and 1 tablespoon of the lime juice. Season with salt and pepper.
Light a grill. In a medium bowl, toss the squid with the oil, orange zest, crushed red pepper and the remaining 1 tablespoon of lime juice and 1 teaspoon of lime zest; season with salt and pepper. Grill the squid over high heat until lightly charred, 4 minutes.
Arrange the watermelon slices on a platter. Drizzle with the dressing and sprinkle with the tarragon and mint. Top the watermelon with the squid, sprinkle with sumac and serve right away.