Croque-asparagus with smoked trout and two cheese sauce

Ingredients

• 24 asparagus
• 1 package of smoked trout of 140 g
• 45 ml (3 tablespoons) of butter
• 45 ml (3 tablespoons) of flour
• 250 ml (1 cup) of milk
• 125 g of smoked salmon cream cheese
• 60 ml (1/4 cup) of grated Gruyère
• Salt and pepper up to taste
• 4 bread slices
• 45 ml (3 tablespoons) of grated Parmesan