Prepare a grill for high heat. Grill corn, turning occasionally, until charred and cooked through, 6–8 minutes. Let cool; cut kernels off cobs and place in a large bowl.
Transfer peppers onto the grill, turning occasionally, until blackened in spots and nearly cooked through, 10-ish minutes. Let cool; cut into 1" strips, retaining as much charred skin as possible; add to corn.
Transfer tomatoes into a small grilling basket and put on grill for 3-5 minutes until just about to burst. Remove and let cool. Arrange everything on a large serving platter and gently toss to combine. Drizzle dressing over and toss to coat; season with salt and pepper.
Notes
This would be great with chicken, beef or salmon on the side or on top!!