Preheat oven to 400°F. Cut 2 apples in half; set aside. Cut the remaining apple into thin slices; cover lightly with plastic wrap, and set aside. Season pork chops evenly with pepper and 2 ¼ teaspoons salt. Heat oil in a large oven-safe skillet over high until smoking. Cook pork chops, undisturbed, until browned on one side, 3 to 4 minutes. Transfer pork chops, browned side up, to a large plate; set aside.

Wipe skillet clean, and add bacon. Cook over medium, stirring occasionally, until rendered and crisp, 5 to 7 minutes. Transfer bacon to a paper towel–lined plate, reserving drippings in skillet; set aside.

Return skillet with drippings to medium-high. Add sage and halved apples, cut sides down; cook, undisturbed, until sage is crisp, 1 to 2 minutes. Transfer sage to plate with bacon. Add sliced apple and shallots to skillet with halved apples. Cook, stirring often, until shallots are softened, 3 to 5 minutes. Stir in flour; cook, stirring constantly, for 1 minute. Add apple cider and mustard. Cook, stirring constantly, until sauce is thickened and smooth, 2 to 3 minutes. Stir in remaining ¼ teaspoon salt. Remove from heat.

Place pork chops, browned side up, in skillet, nestling apple halves between pork chops. Sprinkle with bacon. Transfer skillet to preheated oven; bake until a thermometer inserted into thickest portion of pork registers 140°F, 10 to 15 minutes. Remove from oven; season to taste with salt. Garnish with crisped sage.