When potatoes are fall apart tender, drain off most of the water (I usually don’t even get all of the potatoes into the strainer, just enough to get out most of the water). Add cashew milk and 1 tsp sea salt and mash with a potato masher or hand mixer (but be careful if you are using a nonstick pot, I did some damage with my hand mixer once). Taste and add more salt to taste. I also usually have some plain (NOT vanilla), unsweetened almond milk on hand that I add if they need a little more liquid.