Technical Stages :

• Peel carefully the asparagus.
• Cut the base by several centimeters.
• Drop the asparagus in salted boiling water and cook for about 20 minutes.
• Drain and reserve.
• Béchamel: Melt the butter in a saucepan, add the flour and mix thoroughly.
• Cool this roux blanc and pour 40 cl of the asparagus water along with 25 cl milk.
• Boil and cook 4 to 5 minutes stirring constantly.
• Add salt, pepper and a touch of nutmeg.
• Turn on the grill of the oven.
• Place the asparagus in a buttered gratiné pan then coat with the sauce.
• Sprinkle with grated Swiss cheese.
• Bake under the grill of the oven and leave to gratiné.
• Serve immediately.