Season the pork with the thyme and 1/4 teaspoon of the pepper.

Lightly coat 2 nonstick skillets with vegetable cooking spray and place them over high heat. When they are hot, add the pork and cook it for 2 to 3 minutes on each side. Transfer the meat to an ovenproof platter and keep it warm in a 180° oven while you make the sauce.

Divide the onions between the skillets and sauté them for about 3 minutes, until they are softened. Combine all the onions in 1 of the skillets.

Add the vinegar, water, sugar and cumin or caraway seeds to the skillet. Stir in the apples, salt and the remaining 1/2 teaspoon pepper. Cover and boil the mixture gently over medium heat for 4 to 5 minutes, until the liquid is almost gone and the apples are moist and tender.

Return the pork (and any juices that have accumulated on the platter) to the skillet and reheat for 1 to 2 minutes. Serve immediately.