Melt the butter in a medium saucepan over medium heat.
Add the flour and cook until browned.
Add the milk and simmer until thickened.
Season with salt and pepper.
Panko Coating
Stir together the panko and melted butter.
Assembly
Preheat oven to 350.
Grease a large baking dish.
Fill the shells with the filling. Place in the baking dish.
Spoon the sauce over and between the stuffed shells.
Sprinkle the panko crumbs on top of the shells.
Notes
Salmon: We prefer to use freshly smoked salmon in this recipe. Simply, smoke a couple of filets at 225 for 40 minutes. Alternatively, you can bake or pan-fry the salmon. Cold-smoked store-bought lox is not recommended.