- In a large saucepan over medium heat, melt butter. 
- Gradually add flour, stirring constantly, until smooth and free from lumps. 
- Gradually stir in milk until sauce comes to a gentle boil, stirring constantly; remove from heat. 
- Add Parmesan cheese and stir until melted and well blended. 
- In a small bowl, beat egg. 
- Gradually add 1 cup of hot cheese sauce, 1/3 cup at a time, to the egg, stirring constantly. 
- Gradually add egg mixture to remaining sauce, stirring constantly until well blended; add salt and pepper to taste. 
- Fold in whipped cream. 
- For each Hot Brown sandwich, place two slices of toasted bread on a metal (or flameproof) dish. 
- Cover the toast with a liberal amount of turkey. 
- Pour a generous amount of sauce over the turkey. 
- Sprinkle with additional Parmesan cheese. 
- Place entire dish under a broiler until the sauce is speckled brown and bubbly. 
- Remove from broiler, sprinkle with diced pimientos, cross two pieces of bacon over the top, and serve immediately.