There are two tricks to great vegan sour cream. First: if you're intending to eat vegan regularly, consider investing in a powerful blender to ensure the smoothest possible puree. Second: Find out the best place to source nutritional yeast--the flavor is phenomenal.
1 cup cashews, soaked in water overnight
1/4 cup + 2 Tbsp. lemon juice
1/4 tsp. salt
1 tsp. nutritional yeast
1/2 cup water