Cowpoke Sandwich

Ingredients

 * 1 large onion, sliced thick
 * Cilantro and Mexican oregano, dried, crumbled
 * Salt and pepper
 * Bread slices, buttered
 * Vinegar and water, in equal amounts
 * Cayenne pepper, to taste

Directions
Put onion slices in a bowl. Coat with spices, then cover with water and vinegar mixture. Refrigerate for 8 to 10 hours.

Drain onion slices, season with salt, pepper and cayenne. Place between two slices of buttered bread.