Sprinkle a pinch of kosher salt onto the minced garlic. Then, using the flat of your knife, squish the garlic into a paste. You should end up with about 1 tbsp.

Put the garlic paste in a small saucepot along with half of the butter. Put the pot on medium heat. Let the butter come up to a froth, then turn the heat down to low. Once the frothing slows and the garlic just starts to change colour, remove the pot from the heat. Don't wait until the garlic browns, because it'll keep cooking and may burn. Add the white pepper and a pinch of salt and set aside.

Boil the potatoes in a large pot of salted water until they're fork tender. Drain well, then return the potatoes to their pot. Add the garlic butter, remaining unsalted butter, and heavy cream. Mash the potatoes until no large chunks remain, then stir until uniform. If the potatoes are too dry, add whole milk a few tbsp at a time. Try not to stir too much or the potatoes will become gluey. Season with salt to taste. Serve with a sprinkle of chives on top.