Tamarind fruit dangles from huge hardwood trees throughout Southeast Asia in big, fat, C-shaped pods. They ripen to a rich, soft, dark pulp, filled with seeds and enclosed in a brittle, light brown shell. Tamarind liquid is made by soaking ripe tamarind pulp and pressing it through a strainer to create a thick, luscious purée that is earthy brown, smoky, sour, and sweet. You can buy blocks of tamarind pulp, processed enough to remove most of the seeds and stringy stuff between you and the lovely smoky-sweet-sour flavor it provides. You still need to soak, mash, and strain out the essence, a messy bit of work for a quick and easy cook. To make tamarind liquid, put about ½ cup of tamarind pulp in a bowl with 1 cup of warm water. Soak for 15 to 20 minutes, pressing and mashing now and then to soften the pulp and mix it with the water Strain through a fine-mesh strainer into another bowl, pressing and scraping with a large spoon to extract as much liquid and purée as you can. You will have about 3/4 cup. You can also buy ready-to-use tamarind liquid imported from Thailand. It looks a lot like apple butter, dark and thick, and it is delicious. You’ll also see the Vietnamese words for tamarind liquid, nuoc me chua, on the label.