These hot summer days call for crisp, refreshing foods, and the vegetable best suited to the task is the cool, crunchy cucumber.

Take those Persian cucumbers — small, thin skinned, practically seedless and plentiful at our farmers markets. They're convenient and especially easy to use: no peeling, no seeding, just scrub and chop, slice or grate for snacks, salads, sauces, sandwiches and soups. And they're universal.

In China, people buy whole chilled cucumbers from street vendors to eat on the go. In Thailand, cucumbers are mashed or sliced and soaked in water and mint to make a refreshing drink. In Japan, they're grated and tossed into vinaigrette of soy sauce, rice vinegar, garlic and sesame oil, spiked with chiles. Throughout the Mediterranean, cucumbers are essential in a variety of cooling salads, soups and sauces.

But our favorite is tzatziki, the ubiquitous Greek yogurt-cucumber condiment.

Variations on this delicious, cooling combo include cacik in Turkey, tarator in the Balkans, and raita in India. The yogurt may be from cow, sheep or goat's milk, but it must be strained and very thick. It's mixed with smashed garlic and finely chopped or grated cucumbers that are first drained. In the Balkans, this sauce becomes a soup when enriched with ground walnuts.

In Greece, tzatziki is served on gyros sandwiches, grilled lamb kebabs and roasted chicken. Thanks to its garlicky goodness, it will disappear quickly when served with grilled pita bread, chips and crisps. Tossed with whole grains — such as barley, wild rice, brown rice, wheat berries, couscous or quinoa — it makes a wonderfully hearty and satisfying main dish salad.

While some recipes call for sour cream and others for nonfat yogurt, we like whole milk Greek-style yogurt best. Sour cream makes the sauce too thick and rich and lacks yogurt's distinctive tang, while nonfat yogurt has less body. Be sure to avoid yogurts with fillers and stabilizers, as they can make the sauce seem gummy.

It's important to let the cucumbers drain to release their liquid before adding to the mix; this keeps it from becoming watery. Let the tzatziki "rest" for at least 30 minutes or longer in the refrigerator before using to give the flavors a chance to marry.

While today's recipe calls for mint and parsley, feel free to alter the herbs to your tastes — dill, basil or cilantro are fine options, too. In lieu of lemon juice, try a splash of lime juice or red wine vinegar.

The sauce will keep about a week in the refrigerator, so double the recipe to have on hand and you're ready for those last-minute guests or an impromptu picnic at the lake.

Tzatziki

Serves 6 to 8.

Note: Serve this as a dip with sliced vegetables and grilled pita chips, spoon over lamb burgers, or as a sauce for grilled lamb, shrimp and chicken. Toss it into grain salads, or thin it with a little buttermilk for a refreshing soup. Be sure to use the Persian cucumbers — they're thin and thin-skinned, and practically seedless. If using the more familiar garden cucumbers, it's best to peel and seed them first. From Beth Dooley.

• 1 to 2 Persian cucumbers (see Note)

• 2 c. whole-milk plain Greek-style yogurt

• 3 garlic cloves, smashed

• 2 tbsp. chopped fresh mint, or to taste

• 2 tsp. lemon juice

• 1 tbsp. extra-virgin olive oil

• Salt and freshly ground pepper, to taste

Directions

Grate the cucumbers and set in a colander in the sink to drain for at least 20 minutes.

In a medium bowl, beat together the yogurt, garlic, mint, lemon juice and olive oil. Stir in the drained grated cucumbers. Season to taste with salt and freshly ground pepper. Cover the sauce and allow to rest in the refrigerator for at least 30 minutes or overnight before serving.

Nutrition information per each of 8 servings:

Calories95Fat8 gSodium4 mg

Carbohydrates4 gSaturated fat4 gTotal sugars3 g

Protein2 gCholesterol20 mgDietary fiber1 g

Diabetic exchanges per serving: ½ carb, 1 ½ fat.

Beth Dooley is the author of "In Winter's Kitchen." Find her at bethdooleyskitchen.com.