- 1 small red onion, very thinly sliced
- 1/2 cup red wine vinegar
- 1 tablespoon sugar
- Kosher salt
- 1/4 cup coarsely chopped oil-packed Calabrian chiles from a jar
- 4 large zucchini (about 2 pounds total), halved lengthwise, leaving stems on
- 3 tablespoons plus 1/4 cup olive oil
- 1/2 cup torn mint, plus more for serving
- Prepare a grill for medium heat. Combine onion and vinegar in a large bowl and let sit 10 minutes. Mix in sugar and a generous pinch of salt, then add chiles; set chile mixture aside.
- Toss zucchini on a rimmed baking sheet with 3 Tbsp. oil; season with salt. Grill, turning halfway through, until steamy and tender within and charred all over, 12–16 minutes. Transfer back to baking sheet and let cool slightly.
- Tear zucchini into 1 1/2″–2″ pieces and add to reserved chile mixture. Add remaining 1/4 cup oil and toss to coat; season with salt. Add mint and toss gently just to distribute. Let sit 5 minutes to allow flavors to come together.
- Transfer zucchini mixture to a platter with a slotted spoon; top with more mint.