Sorrel is a tricky one. Not because it’s difficult to use, but because so few people know what to do with it!
Here’s another CSA’s website post of sorrel recipes, be sure to read down to some of the gems hidden in the comments section: http://twosmallfarms.blogspot.com/2007/03/sorrel-recipes.html
And here is a link to a few more recipes on Epicurious.com.
Happy cooking, and hopefully you got to stop by and say hello at the Boulder Jewish Festival today! It was a beautiful (though windy) day to be out talking about our CSA and our wonderful farmers.