Pressure Cooker:
Brown pork and vegetables as above, using saute setting of a 6-quart electric pressure cooker or a 4- to 6-quart stove-top pressure cooker. Add all pork and broth to cooker. Lock lid. Set electric cooker on high pressure to cook for 15 minutes. For stove-top cooker bring up to pressure over medium-high heat according to manufacturer’s directions; reduce heat enough to maintain stead (but not excessive) pressure. Cook 15 minutes. Quick release the pressure. Carefully remove lid. Stir in squash and apples. Use saute setting or return to stove-top; simmer, covered, 25 minutes or until squash is tender. Season to taste with additional salt and black pepper. Serve as above.
Slow Cooker:
Brown pork as above. Transfer to a 4- to 6-quart slow cooker. Add leeks, celery, squash, and broth to cooker. Cover; cook on low for 7 hours or on high for 3 1/2 hours. Stir in apples. Increase to high if using low. Cook 30 minutes more. Serve as above.