Baked Spicy Onion Slices
from Chez Panisse Vegetables by Alice Waters

oonion

Onions cooked this way can be served warm or cold, as a side dish, or by themselves.  Sweet, juicy yellow onions are best for this recipe.  Peel them, slice them 1/4-inch thick, season well with salt, and place them on a well-oiled baking sheet.  Brush the exposed sides of the onions with olive oil and bake them in a preheated 375 F oven for about 30 minutes, or until the onions are soft, and browned on their undersides.  When the onions are cooked, place them carefully in a shallow dish, keeping the slices intact.  Pour over them a vinaigrette made with 1 part sherry vinegar, 4 parts extra virgin olive oil, salt and a pinch of ground cayenne or hot pepper flakes.  Let the onions marinate in the vinaigrette for about 20 minutes.  Serve them cool, or warm them gently in the oven.  Sweet red onions are also good baked this way.  Peel, slice, season, and brush red onion slices with oil as above, then sprinkle some good balsamic vinegar over them.  As they bake, the vinegar helps them caramelize.  Either serve them warm right off the tray or dress them in a shallow dish with olive oil and a little more balsamic vinegar and marinate them a while first.