1 Make souffle: Separate eggs, putting whites into medium-size bowl, yolks into large bowl.
2 Peel, pit, and mash avocado by pressing through a sieve with a wooden spoon.
3 Melt butter or margarine in medium-size saucepan; remove from heat; blend in flour, salt, liquid red pepper seasoning, and onion; slowly stir in milk.
Cook over low heat, stirring constantly, until sauce thickens and boils 1, minute; remove from heat.
Blend in avocado; cool.
4 Beat egg whites just until stiff enough to hold their shape but still moist.
5 Beat egg yolks well; slowly stir in cooled avocado mixture; lightly fold in beaten whites until no streaks of sauce or egg white remain; pour into ungreased deep 6-cup baking dish.
6 Bake in moderate oven (375°) for 50 minutes, or until top is firm and golden; serve at once With hot FONDUE SAUCE.
7 While souffle bakes, make sauce: Melt butter or margarine in small heavy saucepan; remove from heat; blend in flour, salt, and pepper; slowly stir in milk, mushrooms and liquid, and cheese.
Cook over low heat, stirring constantly, until sauce thickens and boils 1 minute.