This recipe works best with 1/2-inch-thick spears. Work quickly when tossing the asparagus with the egg whites, as the salt will rapidly begin to deflate the whites.
Normally, keftedes are made with ground meat (they're basically meatballs). These vegetarian alternatives are packed with flavor.
For a 4-to-6-cup soufflé mold or straight-sided baking dish 8 inches across, serving 4. You can bake this in a 4-cup mold with a paper collar, into which the soufflé will puff 2 to 3 inches over the rim and hold its puff when the collar is removed. Or bake it in a 6-cup mold, which will give you a more stable soufflé but less puff.