Slice the eggplant, zucchini and squash lengthwise into ¼-inch thick strips. Slice the onions into rings. Cut the peppers, top to bottom, into 4 flat pieces each.
Grill all the vegetables over medium-high heat until softened and somewhat charred.
Remove to a cutting board and cut into ½-inch long strips. Sprinkle liberally with salt and pepper.
Mix in a bowl with the vinegar and olive oil. Serve garnished with cherry tomatoes and basil.