In a large pot, melt 2 tablespoons unsalted butter over med-low heat. Add mushrooms. Cook until soft and liquid escapes, about 10 minutes. Set aside a few mushrooms to garnish later.

Add chicken stock, celery, onion, and parsley. Bring to a boil, reduce heat and simmer for 20 minutes.

Meanwhile, make your white sauce. In a medium saucepan, heat 1 tablespoon butter over med-low heat. Whisk in the flour working through any clumps. Slowly add 1 cup milk and whisk in to keep mixture smooth. Don't let boil but keep warm.

After mushroom mixture is done simmering, transfer to a blender and blend until smooth. Return to pot. Slowly add milk mixture to soup and stir until heated through. Add salt, pepper, paprika, and nutmeg.

To serve, top with freshly chopped chives and parmesan cheese and those mushrooms you set aside. ENJOY!