Liam,
French Sorrel is a herb that is delicious!!!!!! I grow it too and I love it. It's very acidic though and also a bit tart. It does not dry well but you can freeze it or keep it in a plastic bag with a wet paper towel for weeks in the fridge. I use my sorrel in sandwiches and salads a lot but my favorite is French Sorrel Soup. Here's my recipe:
1 Onion
1 Large Russet Potato
1 lb or 2 large bunches of French Sorrel
3 Cups Veggie Stock
Seasoning (no salt Mrs. Dash or similar)
A splash of Soy half and half (if on MWL do not use this)
Saute the onions with some veggie stock until translucent. Cut the potato in small pieces and add the broth and the potatoes to the onion. Cook until tender or about 15-20 min. Cut the stems of the Sorrel and cut them length wise and add to the pot. Cook for about another 5 min until the Sorrel is dark green. Add seasoning. Laddle the stock and the Sorrel into a blender or food processor and puree until smooth. Add it back to the pot and voila you're done. Add some Soy half and half if you like at the time of serving. A few tblsp will do it.
It's delicious and very filling.

You can also add beans, corn etc to the soup and not puree the Sorrel. Here's a few pics:
Blended Sorrel Soup

Not Blended with beans, corn and potatoes
