Pour the chicken stock into the inner pot of the electric pressure cooker. Add the chicken thighs and breasts, then sprinkle the onion powder, garlic powder, paprika and salt over the chicken.

Pour the barbecue sauce over the chicken, then add the grated onion with its juice, the brown sugar and the Worcestershire sauce. Do not stir: the stock has to stay on the bottom so the pot can come to pressure.

Lock the lid and turn the valve to sealing. Cook on manual (high pressure) for 15 minutes. The pot takes a few minutes to come to pressure before the countdown starts.

Let the pressure release naturally for 10 minutes, then turn the valve to venting to release the rest. Open the lid once the pin drops.

Check the thickest piece with a food thermometer: it must read at least 165°F. If it is lower, lock the lid and pressure cook 5 minutes more. Move the chicken to a bowl or cutting board and shred it with two forks or a hand mixer.

If the sauce in the pot looks thin, press sauté and simmer it, stirring often, until it thickens.

Stir the shredded chicken back into the sauce, add more barbecue sauce if you like, and serve.