Place potatoes on a steamer rack in a pressure cooker along with 1/2
cup of water (some cookers require more water - check owner's manual). Lock lid in place & bring to high
pressure. Cook for 11 minutes and let pressure release normally.
Unlock
lid and place potatoes in mixer bowl along with minced garlic and pureed
chipotles. Mix on low speed until potatoes are broken up. With mixer
running, add enough milk to thin the mixture to a smooth
consistency. Season to taste with salt and butter.
These can also be cooked on the stove top. Boil potatoes until tender, drain and mix as above.