1. Preheat oven to 375° F. Cut pears in half from top to bottom. Use a melon baller or small spoon to hollow out the core and some of the center flesh from the middle of each pear half. On the skin side of each half, cut off a small portion of the rounded skin, so the pear will sit flat on a surface. 
2. Add 1 teaspoon of lemon juice to the center of each half. Rub the lemon juice into the pear flesh. Add 1/2 tablespoon of olive oil to each pear, and rub with the oil. Pour apple juice into a small baking dish. Add enough juice to fill the dish by 1/4 inch. Place the pears in the dish, and cover with foil. Cook for 30 minutes.
3. While the pears are cooking, place a skillet over medium heat. Add the pancetta. Sauté for 5 to 7 minutes until cooked through and beginning to crisp. Remove pancetta from pan. Let drain and cool on a paper towel. When cool, add to a bowl. Stir in the remaining three ingredients.
4. Remove pears from oven. Spoon the pancetta filling into the core of each pear half. Bake uncovered for 10 more minutes.

Calories: 320, Fat: 21 g (7 g Saturated Fat), Cholesterol: 25 mg, Sodium: 510 mg, Carbohydrates: 27 g, Fiber: 3 g, Protein: 6 g.