Place potatoes in a pot and cover with water. Salt water and boil potatoes until tender 12 to 15 minutes.
Squeeze the water from spinach in a clean dish towel.
Drain potatoes and melt butter in the hot pot, then add the garlic and cook 2 to 3 minutes. Stir in cream, add the spinach, separating the greens as you do. Season greens with salt, pepper and nutmeg. Add potatoes to the pot and mash to desired consistency.