1. Roast the poblanos over a gas flame until charred all over. Transfer to a plate and let cool. Discard the skin and seeds and cut the poblanos into 1/2-inch dice. 2. In a large saucepan of boiling salted water, cook the corn until tender, about 3 minutes. Drain well. 3, In a large, deep skillet, heat the olive oil. Add the corn and zucchini and cook over moderately high heat, until lightly browned on the bottom, about 5 minutes. Reduce the heat to moderate and add the poblanos, scallions, garlic, shallot and thyme and cook, stirring, for 2 minutes. Transfer to a large bowl and let cool to room temperature. Stir in the tomatoes and cilantro, season with salt and pepper and serve. Make Ahead The salad can be prepared through Step 2 up to 1 day ahead.