Pour 1 cup (8 fl oz / 240g) water into the Instant Pot and insert a steamer basket, then place the 2 lbs (32 oz / 907g) of peeled and quartered potatoes into the basket.

Close and lock the lid, select the MANUAL setting, and set the cooking time for exactly 15 minutes at HIGH pressure.

Once the cooking cycle is complete, allow the machine to do a Natural Release for 15 minutes, then manually release any remaining pressure before carefully opening the lid.

Transfer the cooked potatoes to a large mixing bowl, add 1 cup (8 fl oz / 240g) milk and 3 tbsp. (1. 5 oz / 42. 5g) butter, and mash thoroughly until the mixture is beautifully creamy and completely smooth.

Season the dish evenly with 0. 1 tsp (0. 5g / 0.18 oz) salt and 0. 1 tsp (0. 5g / 0.18 oz) ground black pepper, adjust to your personal taste, and serve immediately.

Warm Your Dairy: Before adding the milk and butter to your cooked potatoes, gently warm them together. Cold dairy drops the temperature of the potatoes and can make them gummy.

Warm dairy absorbs faster and keeps the dish piping hot.

Do Not Over-Mash: The starch in potatoes turns to a gluey paste if overworked. Mash just until the lumps are gone and the texture is smooth. For an ultra-light texture, consider using a potato ricer before folding in your liquid.

Dry Them Out: After pressure cooking and draining, return the hot potatoes to the warm Instant Pot insert (turned off) for a minute or two. The residual heat will evaporate excess surface moisture, allowing them to absorb more butter and milk instead of water.