Making a cheese sauce requires adding grated cheese to a béchamel sauce. This makes what is called a Mornay sauce. Enjoy over seasonal vegetables or use to make macaroni and cheese.
2 tablespoons butter
2 tablespoons flour
1-1/2 cups 2% milk
1 teaspoon Dijon mustard
1 cup shredded Gruyere or Emmantal cheese
salt and pepper
Place saucepan on stove over medium-low heat. Add butter and melt until foaming subsides. Add flour to make a roux. Stir constantly (so it doesn't burn) for about two to three minutes to cook the flour.
Pull the saucepan off the heat and allow to cool slightly. Pour in milk. Return pot to medium heat and bring to a simmer. Stir or whisk constantly until the sauce thickens and is very smooth. It should be just a bit thinner than the consistency you want for your cheese sauce. Add more milk if it is too thick.
Stir in the nutmeg and Dijon mustard.
Remove from heat and stir in the grated cheese until smooth.