To prepare the filling, melt 1 tablespoon butter in a deep skillet over medium heat. Add shallots and sauté until soft and slightly browned. Add salt, pepper and thyme leaves. Scrape into a small bowl.

In the same skillet melt the remaining butter.

Add mushrooms and stir until coated with butter, soft and golden.

Remove from heat.

Beat eggs and cream together until well blended.

Sprinkle about half the Gruyere on the bottom of the pie shell.

Spoon in shallots.

Pour in egg mixture.

Place mushrooms all over the top with the remaining cheese.

Bake 40 minutes at 325 F or until golden brown and mixture is set.