Here is a vegan recipe for excellent mashed potatoes. You can have fun with it and try all sorts of wacky variations, but this basic version is wonderful.
5 russet potatoes, cubed
1 medium or 2 small, parsnips, peeled and cubed
1-2 cups, soy milk (Silk™ is best IMHO)
1 vegetable bouillon cube
salt and pepper
1-3 tablespoons, olive oil or margarine (optional)
chopped green onions
Boil potatoes and parsnips in plenty of lightly salted water. There should be enough water to cover the potatoes and parsnips by at least one inch. Although you should peel the parsnips, peeling the potatoes is a matter of personal preference. I usually do not because the skin adds fiber and nutrients while not diminishing the taste or texture. My wife vehemently disagrees. When I make them for her, I do a half-assed job peeling so that 30-50% of the peeling remains. Sometimes she whines, sometimes not. In any case, use russet potatoes. They have a higher sugar content and are just perfect.
When the potatoes are soft enough to easily mash with a fork against the side of the pot, they are done. Dump them in a strainer or colander, but be careful to reserve about a cup of the liquid. Pour the liquid in a mug or small glass and dissolve the bouillon cube in the liquid. Next comes the tricky part where you will make or break your mashed spuds.
Dump the drained potatoes into a large mixing bowl. Pour in the bouillon broth you just made. Then add the oil or margarine if you are choosing to use it. I sometimes do and sometimes do not because the bouillon cube adds so much flavor that the oil or margarine only seems to add fat. YMMV. Add a small amount of salt and pepper.
Now, with an electric hand mixer, begin to whip the potatoes. Start slow and build speed. Gradually add the soy milk, and continue adding until you reach the desired consistency. I like my spuds a little thicker so I don't usually use much soy milk.
Serve with chopped green onions on the side. This recipe serves 2-3 people with healthy appetites. You can adjust the recipe for larger or smaller crowds by figuring 2 potatoes per person plus one.
Variations. As I said before, there are limitless ways to jazz this dish up. As sydnius and LordOmar indicated above, garlic mashed potatoes are great. You can add whole garlic cloves to the other vegetables as they boil, or you can add roasted garlic during the mashing process. I have heard of folks adding jalapeno peppers while mashing. Carrots add color and a certain sweetness. Of course cheese makes everything better but then this ceases to be a vegan dish. Have fun with it.