Fresh Herb And Cheese Sauce - cooking recipe

Ingredients

1 onion
2 tablespoons butter
1 tablespoon plain flour
1/2 cup vegetable stock
1/2 cup dry white wine
1 cup sour cream
salt and pepper
1 pinch grated nutmeg
7 ounces mozzarella cheese, cut into small cubes
1 small bunch chervil, washed and coarsely chopped
1 egg yolk

Preparation

If you plan to serve this with pasta, put your pasta on to cook now. This sauce would also complement certain meats, chicken, for instance.
Peel and finely chop onion.
Melt the butter, fry the onion, stir in the flour and fry until golden.
Gradually add the stock, and bring the sauce to the boil, stirring constantly.
Add the wine and sour cream and allow to simmer on low heat.
Season the sauce with salt, pepper and nutmeg.
Add the Mozzarella cheese cubes to the sauce and allow to melt over low heat.
Stir the chopped chervil (or herb of choice) into the sauce.
Beat the egg yolk with 2 tblsps of sauce, then blend into the rest of the sauce.
Add cooked pasta of choice (recipe suggestion, tortellini, although I used the homemade gnocchi mentioned above).