Title: Sweet potato soup
 Categories: Soups
      Yield: 6 servings
 
      2 tb Butter
      1 md Onion, finely chopped
      3    Stalks celery, thinly sliced
      5    Sweet potatoes (2 lbs),
           -peeled, grated
      2 lg Apples (Macs), peeled,
           -cored, grated
      5 c  Stock (chick, beef, veg)
  1 1/2 ts Grated orange zest
    1/2 ts Salt
 
  Heat the butter in the cooker. Saute the onions until soft, about 3
  minutes.  Add the celery and sweet potatoes and toss to coat with the
  butter.  Add the grated apples, stock, 1 tsp orange zest, and salt.
  
  Lock the lid in place and over high heat bring to pressure.  Adjust
  the heat to maintain pressure and cook for 4 minutes.  Let the
  pressure drop naturally or quick reduce under cold water.  Remove the
  lid.
  
  If the soup seems too thin, puree about a third of it in a blender
  and stir the puree back into the soup.  Add in the remaining zest and
  salt to taste. Heat thouroughly before serving.