Melt the butter and make sure to remove from heat before butter browns.
Using a blender, blend yogurt, turmeric, lemon juice, worcestershire, salt, pepper and cayenne pepper (optional) for about 2 seconds or until smooth.
While blender is on, add the melted butter in a thin steady stream.
Toast and butter all 4 English muffins topping with 1 slice of proscuitto, and set them on plates.
Bring to a simmer 3 cups of water in a medium size saucepan.
Pour in the vinegar.
Break all 4 eggs into water and cook for 2 to 3 minutes or until whites are set and yolks are still soft.
Place 1 poached egg on each English muffin and spoon a generous portion of cream sauce on top of the eggs, garnish and serve.