Wrap each beet individually in aluminum foil and place in oven in a roasting pan. Roast beets for about 1 hour, until they are knife tender. Let cool. Rub off skins and slice.
Place garlic and shallot in a blender or food processor. Pulse until chopped. Add basil leaves and vinegar. Pulse again. Slowly add oil, processing until smooth. Add salt. Stack beets, tomato and mozzarella slices. Drizzle with vinaigrette.
