Melt 1 tablespoon butter in skillet. Add mushrooms and saute until tender, about five minutes. Set aside. Saute onions, carrots, in an additional tablespoon of butter. Set aside.

Prepare puff pastry shells according to directions; they take about 25 minutes to cook.

Make a roux out of the additional butter over medium heat until bubbling (melt the butter and mix in the flour, bit by bit, whisking with a fork or whisk to remove all clumps before adding more).

Brown the roux to a light brown color, then gradually whisk in the chicken stock. Add the rest of the stock, keeping sauce simmering but not boiling furiously, and add the sherry. Reduce heat to medium and add the vegetables and cubed chicken.

Serve over puff pastry shells. Garnish with chives or parsley.

This is a pretty rich dish. BigOven calculates this at about 917 calories per serving, and about 62g carbohydrate.