Lightly grill eggplant, squash and zucchini. Blacken peppers on grill, place in paper bag for a few minutes, then remove the blackened skin, seeds and slice. On a sheet of plastic wrap layer eggplant, zucchini, squash and peppers. Mix goat cheese and sour cream and spread a thin layer on top of vegetables. Roll. Refrigerate for up to two hours. To serve, slice into 1/4 inch pieces.