Combine spine, neck, and wings of 1 chicken or turkey, 1 onion, 2 stalks celery, 1 carrot, 1 clove garlic, 1 bay leaf, 1 teaspoon whole black peppercorns, 1 handful fresh parsley, 2 bushy sprigs fresh thyme, and ½ teaspoon sea salt in a large pot. Cover with 8 cups of water. Bring to a simmer, partially cover, and gently simmer for about 1½ hours. Strain and discard solids (you can reserve the wing meat for another use). Cool completely before refrigerating or freezing.