Season the beef with a little salt and black pepper and spray the inside of the Instant Pot with low-calorie cooking spray.
Set the Instant Pot to 'sauté' and add the beef. Fry the beef for a few minutes until browned and sealed all over. Add the onion, garlic, peppers and ginger and continue to fry for a further 3 minutes.
Add the carrot, celery, potato, pineapple, chopped tomatoes, stock, tomato puree, Henderson's relish, soy sauce, sweetener and hot pepper sauce and stir well.
Allow the Instant Pot to come to a simmer and then press cancel. Add the lid, lock and set the valve to 'sealing’. Cook on high pressure for 30 minutes. Set the valve to 'venting' and release the pressure.
Add the cornflour slurry, stirring well. Set the Instant Pot to 'sauté' and simmer for 5 minutes until the stew has thickened. Serve with an accompaniment of your choice.