In a blender, combine the first nine ingredients; cover and process until blended. Place tomato wedges in a bowl; add enough dressing to cover. Let stand at room temperature for 1 hour. Pour remaining dressing into a jar; cover and refrigerate for another use.
To serve, use a slotted spoon to place tomato wedges on lettuce leaves; drizzle with dressing left in bowl. Yield: 3 cups.