From Vegetable Literacy by Deborah Madison

I have never made anything with Sorrel, but I saw it out in the field last Wednesday.  It was big and beautiful and I really wanted us all to have a chance with it before it goes over.  In her book Deborah does say that the stems can be quite woody and tough and it is best to discard them.  The leaves will turn to a puree before the stems would ever cook down.  

About 2 cups Sorrel Leaves
1 clove Garlic, pounded to a puree
1/3 cup full-fat Yogurt or Sour Cream
Slivered Chives or Garlic Chives
Sea Salt

If the sorrel leaves are on the mature side, fold each leaf in half lengthwise and pull out the stem along the entire length of the leaf.  If very tender, just remove the stems from the base of the leaf.  Tear the leaves into large pieces.  Put the sorrel, yogurt, and garlic in a food processor and puree until smooth.  Stir in the chives and season with salt.  Cover and refrigerate until ready to use.  This will keep well refrigerated over the course of several days.