Sorrel is a perennial green that can be used like spinach. Some say it has a lemony taste and I have heard it referred to as lemon spinach. Sorrel goes well with fish, eggs, salads, on sandwiches in place of lettuce, in pesto, and most famously: Sorrel Soup
Sorrel is easy to grow and can handle some shade. Use the smaller leaves fresh or cooked and the larger leaves in cooking. Keep the flower heads trimmed for a longer harvest.
Sorrel contains oxalic acid so avoid cooking in aluminum (which is a good idea anyway) or cast iron pans.