- 1 large onion, quartered
- 1 large carrot, cut into 4 pieces
- 1 stalk celery, cut into 4 pieces (optional)
- 1 leftover chicken carcass
- 10 cloves garlic
- 15 whole black peppercorns
- 4 quarts cold water, or more as needed
- 1 teaspoon sea salt, or to taste
- Place the onion, carrot, celery, chicken carcass, garlic cloves, and peppercorns into a large pressure cooker. Add water until it reaches 2/3 of the way up the pot (or until you reach the maximum fill line, according to your pressure cooker's instructions) and seal the lid.
- Bring the pressure cooker up to full pressure over high heat. Reduce the heat to medium-low and cook, maintaining full pressure, for 30 minutes.
- Remove the pot from the heat and allow the pressure to drop naturally. Do not use quick-release methods.
- When the pressure has dropped, remove the lid. Strain the stock into a bowl and discard the chicken bones and vegetables. Let the stock cool to room temperature, and then transfer to the refrigerator . When the stock is cold, any fat will have risen to the surface and solidified. Skim the fat off completely, and season to taste with sea salt.