1tablespooncornstarch or arrowroot powder(10 g; substitute 2 tablespoons tapioca starch)
3/4teaspoonfine sea salt
1/2teaspoonmustard powder
1/2teaspoonsweet paprika
1/2 teaspoononion powder
1/4teaspoonturmeric
Pinchfreshly ground black pepper
Instructions
Blend all ingredients in a blender till smooth. Transfer this mixture to a medium sized saucepan.
Heat the cheese sauce over medium low heat, stirring constantly with a whisk or spoon as you go. Continue heating for 5 minutes, or until the sauce thickens rapidly. Stir vigorously as you go, so that the cheese sauce doesn't form clumps. When the sauce appears thick, smooth, and a little shiny, it's ready.
Use the cheese sauce immediately or store for future use.