Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   1       lb           Fresh medium mushrooms, stems removed
   1       c            Olive oil
                        Grated zest of 1 medium orange
                        Grated zest of 1 medium lemon
     1/2   c            Fresh orange juice
     1/2   c            Fresh lemon juice
   2       large        Garlic cloves, very finely chopped
   2       ts           Salt
   2       ts           Mustard seed
   2       ts           Finely chopped cilantro leaves
     1/2   ts           Cayenne
     1/2   ts           Freshly ground black pepper

Preparation:

Place mushrooms, oil, zests and juices in a non reactive saucepan over high heat. Bring just to a boil and remove from heat. Transfer mixture to a glass jar or bowl, and stir in garlic, salt, mustard seed, oregano,cilantro, cayenne, and pepper. Allow to cool completely, then cover and refrigerate, stirring occasionally, for at least 24 hours before serving. Drain mushrooms and serve.