I use tamarind in all kinds of dishes, but many American cooks aren't familiar with this ingredient, which is mostly associated with Indian and Southeast Asian cooking. The fruits look like long, brown pods; inside is the pulp, dark brown and sticky, with seeds and some membrane embedded within. Luckily, you can buy convenient blocks of the pulp, separated from the pods, in Asian markets. You will need to mash the pulp with some warm water, working it with a fork or your fingers, to make tamarind liquid for use in recipes.
Make the effort to find some, and get to know tamarind. It's a flavor gift to any cook, giving a delicious tart note to many dishes. It's good for sauces where hot-sour is the goal, such as barbecue; balance it with a hint of sugar and suddenly you have great complexity. Try a dash in salad dressings, or make a simple and delectable relish for burgers or grilled meat by cooking up caramelized onions, salting them generously, and then balancing the sweetness with a little tamarind liquid. The final touch is a generous quantity of cilantro or mint.