"There was beer in plenty, and a mighty dish of mushrooms and bacon, beside much other solid farmhouse fare."
-Lord of the Rings, The Fellowship of the Ring Book I: Chapter 4, A Short Cut to Mushrooms
by J.R.R. Tolkien

Fry until barely crispy:
Bacon (to taste)

Remove from skillet; do not drain drippings! Slice bacon into bite-size pieces. Set aside; keep warm.

Melt in skillet with bacon drippings
1 oz butter

Brown in skillet for up to two minutes
1 lb button or chestnut mushrooms
Put lid on and stem until tender, about 5 minutes more or less

Stir in:
1 Tbls. plain flour
¼ pint milk
Heat, stirring continuously until thickened. Simmer for 2 minutes.

Stir in:
2 tsp. wholegrain mustard
2 tsp. chopped tarragon
3 Tbls. sour cream
Bacon pieces

Serve on a nest of chicory and lettuce leaves and garnish with tarragon leaves.