shallots and chopped mint in bowl. Add 1/3 cup olive oil and vinegar. Season to taste with salt and pepper. Add lemon peel. Refrigerate at least 1 hour to blend flavors. Cut eggplants into 1/4-inch slices. Sprinkle with salt and pepper and brush both sides of each slice with olive oil. Place eggplant slices on grill over low coals and cook until eggplant is browned on both sides, brushing frequently with olive oil to keep moistened. Keep warm. When ready to serve, cut yellow tomatoes into 1/4-inch slices. Pour chopped tomato mixture on platter, spreading to cover bottom. Alternately, arrange overlapping slices of eggplant and tomato. Insert mint leaf between each vegetable slice. Sprinkle with salt and pepper and splash of olive oil, if desired.