This is going to be done with a pressure cooker.... It works just fine there is literally no difference unless you're making consume . . . but thats dumb.

1 onion, cut in half skin and all
Whole head of garlic, cut latteraly, skin and all
3 stalts of celery, cleaned
1 leek, cleaned
3 big carrots, cleaned.... skin and all
2 chicken spines
8 whole chicken wings with skin
Any other chicken scraps from the freezer
1 tablespoon peppercorns
Water........

Set your oven to roast at 450

Drizzle a bit of oil on the chicken parts and roast them at 450 for about 10 min
Turn the broil on and broil them for a bit as well.
dont burn them.

In the bottom of your pressure cooker (Regular pressure cooker.... not an instapot.) drizzle a bit of oil and start the heat. Get it a bit hot then drop the oinion and garlic in to give them a little color.

Drop the rest of the veggies and the chicken pieces

Add water to the vessel until the chicken is covered, don't go over your pressure cookers max liquid line ( this is bad if you do )

Lock the lid, set the heat on and wait until the pressure cooker gets to high pressure.

cook at high pressure for 1 hour.

Kill the heat and let it naturally come down to room temp.

Add salt to taste, pack away or freeze.