Clean and rinse the potatoes and cut them in 2-3 cm cubes.

Boil 4 litres of water in a large pot over high heat and add 1 tablespoon of salt.

Put the potatoes I the pot and once it boils again cook them for about 20 minutes until soft (check with a fork).

Take the potatoes out of the water and let them sit for 10 minutes and then press them through the potato ricer into a large pan or pot. Throw away any skin left in the ricer to help with the next batch.

Repeat the process for 3 times to have a smooth mixture and to avoid that the potatoes become gluey.

Put the milk in a small sauce pan on medium heat and once boiled take it off the fire.

Put the pan or pot that the pureed potatoes are in on low heat and with a strong large whisk stir in the milk in slow movements.

Whisk in the butter in small batches making sure that you add the next batch when the previous was incorporated.