With the rack in the middle position, preheat the oven to 425°F (220°C). Line a baking sheet with a silicone mat or parchment paper.
In a pot over medium heat, melt the butter. Add the flour and cook for 1 minute while stirring. Whisk in the milk and bring to a boil. Simmer over medium-low heat for 5 minutes or until the sauce has thickened, stirring regularly. Season with salt and pepper. Cover and set aside.
Place the English muffins on the baking sheet, cut side up. Bake for 5 minutes or until lightly golden.
Spread a small amount of béchamel over the muffins. Top with the shrimp, corn and the remaining béchamel. Sprinkle lightly with cayenne.
Bake for 6 to 8 minutes or until the béchamel is lightly browned.
Remove from the oven and garnish with chives. Serve with a green salad, if desired.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.