In a small bowl, combine the 1 tablespoon freshly ground black pepper, 1/2 teaspoon kosher salt, pinch of cayenne pepper, and 1 teaspoon Dijon mustard. Add 1 tablespoon of the olive oil and stir to mix well.
Rub the chops on both sides with the spice mix. If desired, place the chops on a plate, cover, and refrigerate for up to 1 day (remove the chops from the refrigerator about 30 minutes before roasting).
Preheat the oven to 400°F (200°C).
In an ovenproof skillet over high heat, warm the remaining 2 tablespoons of olive oil. Add the 4 (8-ounce) bone-in pork loin chops, 1 1/2 inches (4 cm) thick and sear, turning once, until golden brown on both sides, 2 to 3 minutes per side. Move the skillet to the oven. Roast the chops until the juices released when pierced with a knife are rosy, or an instant-read thermometer inserted into the center of a chop away from the bone registers 145° to 150°F (63° to 65°C), 13 to 15 minutes.
Meanwhile, in a small saucepan over low heat, warm the store-bought or homemade applesauce. Arrange the chops an a warmed platter or individual plates and garnish with the fresh or fried sage leaves, if desired. Pass the warmed applesauce at the table.