Portabella Mushrooms in a Feta Cheese Sauce

This past weekend while we were at Sam's Club I found these beautiful portabella mushrooms.  I had seen a recipe for in a magazine that called for them.  But when it came time to make the dish I could not find the magazine anywhere.  I could not really find a recipe that wasn't a stuffed mushroom.  So I came up with the following recipe.  When I "create" recipes I tend to just throw this and that into the pan.  Today I tried my best to remember what I put in.  But OH.MY.WORD was this good!!

Portabella Mushrooms in a Feta Cheese Sauce

4-5 Portabella Mushrooms, cleaned and chopped into bite size pieces

1/2 stick of butter or less if you like

1 packet of onion soup mix

2 Tablespoons flour

1/2 box of Chicken or vegetable stock

1 cup feta cheese

Melt the butter over very low heat.  Add mushrooms and cook about 10 mins.  Sprinkle the soup mix over the mushrooms and stir until well mixed.  Continue to cook about 5 minutes longer.   Add the flour and stir until well mixed. 

Stir in the stock of choice and stir until thickened.  Bring to a simmer and then add the cheese.  Cook until melted.  Serve over pasta.