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
minutes. Turn vegetables and bake 10 minutes more. Potatoes and pepper slices may
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
toast bread, about 5 minutes.