1 pint Béchamel sauce
2 oz grated Gruyère cheese
2 oz grated Parmesan cheese
1 T butter
¼ C whole milk, hot
In medium saucepan over medium-low heat, heat béchamel to a simmer.
Add Gruyere and Parmesan cheeses and stir until cheese has melted.
Remove from heat, stir in butter.
Add some or all of the milk to achieve the desired consistency.
Serve over pasta, fish, poultry, vegetables, etc.