Spray the Instant Pot with low-calorie cooking spray and set the Instant Pot to Sauté mode. Add the diced pork and season with a little salt and pepper. Fry until lightly browned on all sides.
Add the onion, garlic and red chilli to the Instant Pot and continue to sauté for a few minutes. In a measuring jug add the stock pot to the water along with the tomato puree, Henderson’s relish, cider vinegar, sweetener, cumin, mustard powder and chilli flakes. Stir to combine. Pour into the Instant Pot and bring to the boil.
Once bubbling, press cancel and place the lid onto the Instant Pot. Set the valve to sealing and set to high pressure. Cook for 30 minutes.
Once the timer has finished, set the valve to venting and allow the pot to naturally release pressure.
Once pressure has released, remove the lid and add the peppers. Set the valve back to sealing and cook for 10 minutes at high pressure. Set the valve to venting and quick release pressure (be careful of the steam!).
Sprinkle with coriander, if using, and serve with your choice of accompaniment.