Snap off tough ends of asparagus. Place asparagus in an 11-x-7-x-11/2-inch baking dish. Add water. Cover dish tightly with heavy-duty plastic wrap, and fold back a small corner to let steam escape. Microwave on high for 6 to 7 minutes or until crisp tender. Set aside and keep warm.

Combine egg yolks and lemon juice in a heavy-bottom saucepan. Add butter, and cook over low heat , stirring constantly until butter is melted and sauce is thickened, for approximately 6 minutes.

Remove from heat; stir in tarragon. Serve with steamed asparagus.

Sauce may be prepared ahead and reheated in microwave.