Directions
Select the 'Sauté' function on your Instant Pot.
Add the butter and allow it to melt completely.
Add the diced onion and cook, stirring occasionally, until softened, about 2-3 minutes.
Press 'Cancel'.
Pour in the water and milk, scraping any browned bits from the bottom of the pot.
Stir in the chopped parsley, lemon juice, salt, and pepper.
Gently place the cod fillets into the liquid in a single layer.
Secure the lid and set the steam release valve to 'Sealing'. Select the 'Pressure Cook' or 'Manual' setting and set the timer for 5 minutes.
Once the cooking time is complete, allow the pressure to release naturally for 5 minutes, then perform a quick release for any remaining pressure.
Carefully open the lid. Gently remove the cod fillets with a wide spatula and serve immediately, spooning the buttery sauce from the pot over the top.