For the truffles: Set up a double boiler over low heat. Add the chocolate chips, almond milk, sugar, vanilla and salt. Cook, stirring occasionally, until the chips are melted and the mixture is well blended. Remove from the heat and stir in the mashed potatoes until completely incorporated.
Transfer the mixture to a loaf pan or small baking dish and refrigerate until firm, about 30 minutes.
For the coatings: Pour the cocoa, pistachios and toasted coconut into separate small bowls.
Using a tablespoon measure or small scoop, scoop out a ball from the chocolate mixture and roll between the palms of your hands. Place in the desired coating, rolling it around to coat, then transfer to a baking sheet. Repeat with the remaining chocolate mixture and coatings.
Store in an airtight container in the refrigerator for up to 1 week.