SOUFFLÉS
Melt 1⁄2 cup butter in a medium saucepan over medium heat. Add 3⁄4 cup flour and stir with a wooden spoon until golden brown, about 3 minutes. The mixture should resemble peanut butter.
Add a quarter of the milk to the mixture and whisk to dissolve flour. Once combined, add remaining milk. Whisk in cheese until combined. Remove from heat.
Place a roasting pan half full of water inside the oven on the lowest rack. Heat oven to 325°F.
Whip egg whites in stand mixer on medium until frothy, about 4 minutes.
Combine egg yolks, mustard, salt, and pepper in a medium bowl. Whisk in cheese mixture until combined. Gently fold in a third of the whipped egg whites. Once combined, fold in the remaining egg whites.
Melt remaining butter and brush the sides of six 6-ounce ramekins. Evenly coat the ramekins with 1 teaspoon of flour and gently tap to remove excess.
Evenlyspoonthesoufflé mixture into the ramekins and place in water bath. Bake 15 to 20 minutes.
Remove from oven and cool on a wire rack for 5 minutes. Remove soufflés by gently tapping bottom of ramekins.
For reheating, heat in oven at 325°F for about 5 minutes.
SHERRY CREAM SAUCE:
Melt butter in a medium saucepan over medium heat. Add shallots and sauté about 2 minutes.
Deglaze pan with sherry, reducing by half. Stir in heavy cream and reduce by half again. Season with paprika, nutmeg, salt, and pepper.
Serve immediately atop warm soufflés.