8 tbsp. room temp. butter
3 cups assorted mushrooms, chopped
1/4 cup chopped shallots
1 large egg
6 tbsp. chopped fresh parsley
1 tbsp. plus 1 tsp. chopped fresh thyme
1 tsp. salt
1/2 tsp. ground black pepper
3 cups breadcrumbs
4 garlic cloves, thinly sliced
2 shallots, thinly sliced
1 cup fish stock or bottled clam juice
4 6-ounce cod fillets
Melt 2 tbsp. butter in heavy large skillet over medium-high heat. Add mushrooms and chopped shallots. Saute until liquid is gone and mushrooms begin to brown. Set aside and allow to fully cool off.
Using electric mixer, beat 5 tbsp butter in large bowl until slightly bubbly. Beat in egg, add then parsley, 1 tbsp. thyme, 1 tsp. salt and 1/2 tsp. pepper. Mix in breadcrumbs and mushrooms.
Preheat oven to 450 Â°F. Sprinkle sliced garlic, sliced shallots and remaining 1 tsp. thyme over bottom of 15 x 10 x 2" glass baking dish. Add fish stock, then fish fillets. Sprinkle fish with salt and pepper. Spoon breadcrumb mixture atop fish, covering tops of fish completely and compressing slightly to bind topping to fillets.
Bake fish until opaque in center, ~ 15 minutes. Then broil until topping is golden, ~ 1 minute.
Remove fish from baking dish with slotted spatula. Transfer cooking liquid to another medium skillet. Simmer over medium heat, add remaining 1 tbsp. butter and whisk just until melted and well blended. Add salt and pepper to taste. Spoon finished sauce around fish.