Most Americans eat some kosher food every day, but chances are they’re not aware of it. Take a walk down the aisles of any supermarket and you will see that certification appears on over 60% of America’s produced foods that are certified kosher, from the coveted Oreo to the thirst-quenching Coca-Cola. Over $150 billion of kosher certified products are consumed annually, and spending continues to rise dramatically.
Melt butter in a large heavy saucepan or top of double boiler set over boiling water.
In a small bowl combine the flour, salt, mustard and cayenne pepper, and then whisk the mixture into the melted butter. Cook and stir for 2 minutes. After the flour mixture is cooked for the two minutes slowly add the milk, whisking constantly, to make a smooth and thick white sauce. Cook for 2 minutes, stirring constantly. Remove from heat. Add grated cheese and stir until cheese is melted.
Whisk egg yolks to break them up. Then add a few Tablespoons of the cheese sauce to them to warm them. Now add the warmed egg yolks back into the cheese sauce and whisk to combine. The sauce may be completed to this point in advance and left at room temperature for an hour.
Beat egg whites with a portable electric mixer until shiny and floppy peaks are formed when beater is withdrawn. Whisk 1/3 of the whites into the cheese sauce. When well mixed, fold the remaining 2/3 of the whites into the sauce.
Pour mixture into the prepared baking dish. Bake about 15 minutes until the surface of the souffle is puffy and brown, but the middle jiggles when the pan is gently shaken. Serve immediately.
To serve, cut portions from the side so that each serving has some firm souffle and some of the saucy part.