Could you describe the Soufflé technique?

All souffles will fall. Anyone who tells you otherwise is selling something. Souffles rise because of the action of steam within them (I don't have my copy on loan, but this is discussed in some detail in McGee, 2004 edition). Popping them back in the oven briefly will resuscitate them enough to take to the table, if they have fallen too quickly.

The key to any Soufflé is the egg whites. The air bubbles trapped inside of them is what causes the mixture to rise. (As daniel mentions McGee puts it at somewhere like 25% due to the air expanding from the heat and 75% from the steam interacting with the bubbles.)

Problems occur because the Soufflé is so reliant on steam and the egg whites setting. If the base dilutes the egg whites then they can't set properly and the bubbles trapped inside of them can't do their job of making it rise. If the whites are just mixed into the base thoughtlessly most of the foam will be destroyed.

Most recipes agree that stiff but moist and glossy peaks are how the egg whites should be beaten.

Souffle technique? Basically, make a bechamel sauce, whisk in egg yolks, stir in seasonings, flavors or foods, fold in stiff beaten egg whites. Put into a prepared souffle dish (greased and coated with any number of different items... depending if you are making savory or sweet souffle). Bake in the center of the oven.

Wikipedia

About 15min in a 190ºC (375°F) oven. I'll ask a separate question about the convection oven.