Preheat oven to 450°F. Wash and cut
eggplant, zucchini, potatoes, and onion into 1/2-inch-thick rounds. Slice pepper into
1/2-inch strips. Halve the tomatoes.
Lightly brush olive oil on cookie
sheet and arrange vegetables in a single layer. Sprinkle oregano on vegetables. Bake
10
minutes. Turn vegetables and bake 10 minutes more. Potatoes and pepper slices may
need
more time. Let cool slightly for easier handling.
Create 4 open-faced sandwiches by
layering vegetables with a little feta cheese. Return to warm oven to melt cheese
and
toast bread, about 5 minutes.