When the inner pot has heated, add 2 tablespoons oil.
Saute onions until the onion juice has evaporated, stirring occasionally, about 8 to 10 minutes.
** Once the liquid has evaporated, stir more frequently to keep the onions from burning; they can burn in seconds!
If the onions begin to stick to the bottom of the Instant Pot, add water, 1 tablespoon at a time, to deglaze. Keep stirring and adding water as needed, but only a little at a time.
After about 5 minutes, the onions will become a thick paste, caramelized and fragrant.
Turn off the Instant Pot and deglaze with more water if there's anything stuck to the bottom of the pot, stirring to loosen any brown bits.
Select the Saute function again.
Add 2 tablespoons oil to the inner pot and add in the marinated pork.
Saute meat for 3 to 5 minutes, stirring constantly.
Deglaze if needed, to make sure nothing is stuck to the bottom of the inner pot.
Press Cancel. Add 3/4 cup water and stir to combine.
Close the lid and select 'Manual' or 'Pressure Cook' and cook for 15 minutes.
Allow the pressure to release naturally (NPR).
Transfer Instant Pot Vindaloo to a serving dish.
Serve with crusty bread or rice.
Prep time does not include steps that are already accounted for in the ingredient list, e.g. minced garlic, cut up pork, etc.
Instead of blending the onions, you can finely chop the onions. In that case, your curry might be less thick.
If you have access to the Goan liquor called 'Feni', finish with 1 to 2 tablespoons after cooking is complete. You can also substitute brandy for the Feni. I suggest adding a little bit to one serving and taste before you add it to the entire dish.
If using store-bought tamarind paste, different tamarind pastes have different strengths. The Indian version is much stronger than the Thai version. If using the Indian version, decrease the quantity.