Whisk all the ingredients up to the tapioca starch (not including the starch) together in your Instant Pot, set on sauté mode and bring to a boil.
Once boiling, whisk the tapioca starch with 2 tablespoons of the hot liquid together in a separate bowl until smooth. While constantly whisking, stir the mixture back into the Instant pot until well combined. Boil the curry until it begins to thicken and reduce, about 10 minutes, stirring frequently.
Once thickened, stir in cauliflower, onion and pepper. Cover the Instant Pot (make sure it’s set to sealing) and cook on manual high pressure for just 1 minute. Let pressure release naturally.
If you want the curry a bit thicker, turn it back to sauté and boil 2-3 minutes.
Serve over rice of choice and garnish with cashews and cilantro.