Saute Shallots In Olive Oil Until Light Brown. In Small Saucepan, Whisk Together Mustard, Chopped Basil, Lemon Juice, Salt And Pepper. Add Poached Egg And Whisk Well To Break Up Egg. Place Over Low Heat And Add The Shallots And Olive Oil. Whisk Until Emulsified. Stir In Tomato Puree And Chervil. Remove From Heat, Cover And Keep Warm. Place Basil Leaves On The Bottom Of The Steamer Rack, Place Fillets On Top Of Basil. Sprinkle With Salt And Pepper. Steam For 5 Minutes And Serve Topped With Sauce.