The tomatillo, a close but very independent cousin of the tomato and Cape gooseberry, is known by several names, including husk tomatoes, jam berries and Mexican green tomatoes. Though widely available year-round, the main season is May through October. Allowed to mature, tomatillos may range in color from yellow to red, even purple. But they're best picked just before ripening, when the flesh is still firm and the flavors are bright with a gentle but assertive acidity. Look for firm fruit with tight, unwrinkled husks.
With husks on, tomatillos keep for about two weeks stored in a paper bag and refrigerated, but husk them and store refrigerated in a plastic bag and they keep up to four weeks. If you garden and find yourself with an abundance, try freezing them (spread them, sliced or whole on a sheet pan in the freezer until solid, then place them in an airtight freezer bag).
In Spanish, tomatillo means "little tomato," and records show that tomatillos were cultivated by the Aztecs as far back as 800 B.C. Tomatillos liven many Latin American recipes with their vibrant color, often silky texture and mildly tart flavor. They're often used in salsas, especially those that lighten rich chicken and pork dishes.
Tomatillos lend themselves to a variety of cooking methods such as roasting, sautéing and stewing. Cooking softens the acidity and brings out the sweetness in the fruit. And like tomatoes, tomatillos can be enjoyed raw. Eat the fruit by itself, or use it to punch up a salad or cold dish.
For a simple meal, try grilling tomatillos -- direct heat over a hot fire brings out the sweet notes of the fruit -- by cutting them into wedges and lightly oiling and seasoning them. Quickly grill the tomatillos so they're crisp-tender -- a couple of minutes per side -- then toss them with some quick-grilled scallions, serrano chile and marinated, grilled shrimp. Divide the mixture among freshly warmed tortillas, add a side dish -- and supper is served.
Or try a variation on classic chile verde by using them in a sauce for a fluffy omelet made with panela cheese (a fresh Mexican cheese that softens to rich creaminess when heated). Sauté diced pancetta and tomatillos with minced onion and garlic. The pancetta cooks until caramelized and crisp; the tomatillo is added just so it warms through and blends with the flavors in the pan.
Freshen up the classic pairing of tomatillo and pork by adding citrus and fresh basil, mint and oregano. Stud a boneless pork roast with slivered garlic. Brown it in a heavy-bottomed casserole. In the same pan, sauté onion, garlic, serrano chile and coarsely chopped tomatillos, then place the roast back in the pan. Add some broth, orange zest and fresh oregano and roast until the meat is falling-apart tender.
Finish the dish by adding some fresh basil, mint and more oregano to the sauce (there is no cilantro in this variation ) along with some fresh lime juice. Spoon the rustic sauce over the pork and serve with rice or grilled tortillas.