Dressing: Put all the dressing ingredients into a blender and pulse until smooth.
Vegetables: Slice the tomato, eggplant, mushrooms and zucchini into 1cm round slices.
Preheat the BBQ to a medium heat and brush with oil. Add the vegetables and cook, turning once until starting to soften and with good grill marks.
To Serve: Stack the vegetables with the largest slice at the bottom working to the smallest at the top. Sprinkle with the crumbled fetta then drizzle with the tomato dressing. Top with basil leaves.