Traditional mashed potato methods call for butter, milk and seasonings. But if you don't want milk in your mashed potatoes -- for any reason -- you can substitute another liquid. While you may have to tweak other ingredients in your mashed potatoes to make them taste just right, ultimately, the potatoes you use -- fresh, starchy and firm, such as Yukons -- contribute heavily to the taste and texture of the dish.
Scrub and rinse the potatoes with a vegetable brush to remove loose dirt. Peel the potatoes and dice them into approximately 1/2-inch pieces. You also can boil them whole, but dicing helps them cook faster if you need to get dinner on the table quickly. Boil the potatoes for around 20 minutes or until soft.
Dissolve around two soup cubes per cup of warm water to use as the liquid in your mashed potatoes; you can use store-bought broth as well, which comes pre-made in a carton or can. Other substitutes include nondairy milks such as soy, coconut or almond. Or, for extra-rich mashed potatoes, use half-and-half, real whipping cream or buttermilk.
Set a colander in the sink and drain the water off the potatoes when they're done. Transfer the potatoes back to the warm pot immediately and add a pat or two of butter or your preferred fat such as olive or avocado oil. Mash the potatoes to blend in the fat quickly. Fat acts as a barrier to keep the mashed potatoes from becoming sticky, so if you're watching your fat intake, cut down the amount of fat you use, but don't eliminate it completely.
Warm your liquid of choice for a few seconds in the microwave and slowly drizzle it into the potatoes; continue mashing them until they're smooth. You can always add more liquid to get your desired consistency, which is easier than correcting watery mashed potatoes. Season the mashed potatoes with salt and pepper.