Prepare the broth and combine with the coconut milk, white wine and mustard. Set aside.
On low heat, slowly melt the butter in a sauce pan. Whisk in the rice flour and simmer for about 2 minutes to make a roux.
Combine with nutritional yeast, turmeric, kala namak salt and the lemon juice, stirring constantly.
Adjust the texture using plant-based milk and serve immediately.