Preheat the oven to 180°C (350°F) and place the potatoes on a rack in the oven
The potatoes should take at least 45-50 mins to be baked through.
Test with a wooden skewer – the skewer should slide easily though the potatoes — or use an instant read thermometer.
The internal temperature you’re after is 100°C (210°F)
When the potatoes are baked through, as soon as you can handle the potatoes (I use an oven mitt) halve them and using a dessert spoon, scoop out the potato flesh into the ricer.
Rice each potato as soon as you’ve scooped it out.
Push the mash through the tamis and then into a saucepan set over medium-low heat. Using a silicone spatula, constantly mix the mash until the mix is drier and ‘fluffier’.
Slowly add the warmed milk a splash at a time. Make sure each splash of milk is incorporated before adding the next.
If you’re not serving straight away, you can now take the mash off the heat and keep in a warm place.
When ready to serve, add the butter a cube at a time to the saucepan over medium heat. After incorporating half of the butter, season with freshly ground salt and taste.
Add the remaining butter and check seasoning again.
Serve immediately.