Place bread cubes in single layer in a 12x7x2-inch baking dish. Microwave at high 3 minutes. Stir once or twice. Remove all but 1 cup croutons from dish.
Divide all vegetables in half. Make a layer of some croutons, and a half each of tomatoes, zucchini, yellow squash, dill pickles, scallions and cucumber. Make second layer with remaining vegetables. Pour pickle liquid over all. Sprinkle with cheese and remaining croutons. Microwave, covered, on high for 20 minutes. Serve hot.