To make this dairy-free and vegan, make the following substitutions:
¼ cup vegenaise
¾ cup raw cashews soaked for 3 hours, then drained
1 cup water
2 Tablespoons lemon juice
everything else the same
A high-powered blender does a good job blending the cashews until they’re creamy. If you don’t have one, do this in a food processor.