Kaffir lime leaves (Recipe: hot and sour shrimp soup)
If I lived in Thailand, or Malaysia, Sri Lanka or Australia, California or Florida or anywhere warmer than Rhode Island, I'd plant a leprous lime tree at the entrance to my house.
I know what you're thinking.
A leprous lime? Lepers??? Gosh, that sounds awful.
You're right. I'm not much of a gardener, and the Citrus hystrix isn't called "leprous" for nothing; the fruits are strangely lumpy-bumpy and, well, not very pretty. But when a plant is reputed to ward off evil spirits and the juice of that fruit makes a dynamite shampoo, I'd definitely take a chance. And when that plant also produces kaffir lime leaves, an essential ingredient in my favorite hot Thai soup, I'd oh-boy-yes want one in my garden.
Kaffir lime leaves -- also called makrut -- have a distinctive two-lobed shape, a glossy appearance, a leathery texture, and an unusual lemon-lime flavor. Leaves can be used fresh or dried. Fresh leaves will keep in a plastic bag in the refrigerator for a few weeks, and in the freezer for up to a year, and either way are much preferred to the dried leaves.
(The kaffir lime rind can be used like lime zest, but the juice is more bitter and assertive than our common Persian limes, so it's seldom used in cooking. You can substitute Persian lime for kaffir lime, but not the other way around.)
To prepare the leaves, break apart the two lobes. If your recipe calls for the whole leaf, you're good to go. Otherwise, fold each leaf in half lengthwise, and cut out the central rib. Then julienne the leaves into a fine shred for curry beef, or mince to use in salad dressing.
Hot and sour shrimp soup (tom yom koong)
An easy version of my absolutely favorite Thai soup, the name of which is transliterated a dozen different ways (tom yum gung, dom yam kung, etc.). Authentic spices and condiments make all the difference between this and a lime-flavored chicken soup. Serves 4 as a starter.
2 cups low-sodium or homemade chicken stock, or vegetable stock
1/2 lb medium shrimp, shells removed and reserved
2 Thai bird chiles, seeds removed, sliced (use more, or less, to taste; for fiery hot soup, leave the seeds in)
1-inch piece of lemongrass
2 fresh kaffir lime leaves, or 1/2 tsp grated lime zest
1 cup canned straw mushrooms, sliced in half lengthwise
3 Tbsp fresh lime juice (from 2 limes)
3 Tbsp fish sauce
In a sauce pan, simmer the stock and reserved shrimp shells for 20 minutes. Strain, and return the stock to the pan. Add chiles, lemongrass and lime leaves, reduce heat to simmer, and cook for 5 minutes. Remove lemongrass and lime leaves, and add the shrimp and mushrooms. Cook for 2-3 minutes, until shrimp are done but not overcooked. Stir in the lime juice and fish sauce, cook for 1 minute until flavors combine, and serve hot.
More recipes in The Perfect Pantry:
Salt and pepper prawns