½ cup dry white wine (or chicken broth, but better with wine!)
1 egg yolk, beaten
⅓ cup shredded Swiss cheese
¼ to ½ teaspoon salt (I used the ½ teaspoon)
¼ teaspoon ground nutmeg
2 Tablespoons grated Parmesan cheese
Instructions
Cook asparagus until just tender. (steam, boil, or roast)
Cook and stir shallot in butter in medium saucepan 2 to 3 minutes; stir in flour. Cook and stir until mixture is smooth and bubbly. Remove from heat; stir in milk. Return to heat and heat to boiling, stirring constantly. Boil and stir for 2 minutes. Stir in wine; remove from heat.
Stir half the wine sauce gradually into beaten egg yolk; return to saucepan. Heat, stirring constantly, until hot. Stir in Swiss cheese, salt, and nutmeg; cook and stir until cheese is melted.
Heat oven to broil setting. Arrange cooked asparagus in lightly greased 1-1/2 quart au gratin dish or baking dish. Pour sauce over asparagus and sprinkle with Parmesan cheese. Broil until cheese lightly browns. Serves 4.
Recipe by The Culinary Cellar at https://theculinarycellar.com/sphere-magazine-aprilmay-1975/