Grilled Meatballs with Yogurt Sauce and Onion Salad

FOR SAUCE: Line a large sieve with cheesecloth (muslin), place it over a bowl and spoon the yogurt into the sieve. Refrigerate for 4-6 hours to drain off the excess water. You should have 1 1/2-2 cups drained yogurt. Add the garlic, olive oil and vinegar or lemon juice to the drained yogurt. Stir well and fold in the mint. Season to taste with salt and pepper. Cover and refrigerate until needed. Prepare a fire in a charcoal grill or preheat a broiler.

FOR SALAD: Cut any large onions in half and then thinly slice all of the onions. Place the onion slices in a large sieve or colander, add the salt and toss well. Let stand for 15 minutes. Rinse the onion slices with cool water and pat dry with paper towels. Place in a bowl and add the parsley and the sumac, if using. Toss well and set aside.

FOR MEATBALLS: In a bowl, combine the lamb or beef, grated onions, garlic, eggs, thyme, pepper and the 1/2 teaspoon salt. Mix with your hands until the mixture holds together well. Form into 12 ovals about 3 inches long and 1 1/2 inches wide and thread them onto metal skewers.

Brush the meatballs with olive oil and sprinkle with salt. Place the skewers on an oiled grill rack or a broiler pan and grill or broil, turning to brown on all sides, until cooked through, about 8 minutes.

Remove the skewers from the grill or broiler and slip the meatballs off the skewers. Cut the pita breads into halves and tuck a meatball into the each half. Serve at once. Offer the yogurt sauce and onion salad at the table for guests to add to taste.