In a small saucepan, melt the butter over medium-low heat.
Add nutritional yeast, cornstarch, xanthan gum, turmeric, paprika, and mix.
Increase to medium heat; add water and milk gradually, stirring constantly. Cook until the mixture thickens slightly. Remove from the heat and set aside.
At this point, you can add Annatto oil extract to deepen the color. Add it gradually, while stirring, until you get the desired color. Cool for a few minutes, then add the black salt and mix well.
The yolk sauce keeps in the fridge for about a week.
