How to Make It
Butter six 6-ounce or four 8-ounce ramekins and coat with bread crumbs, tapping out any excess. Set the prepared ramekins in a large shallow roasting pan.
Melt the butter in a medium sauce-pan. Add the flour and whisk over moderate heat until bubbling, about 1 minute. Add the milk and 1/4 teaspoon of salt and whisk until the mixture boils and thickens. Remove the pan from the heat and whisk in the egg yolks, then whisk vigorously over moderate heat until the mixture boils again. Whisk in the lemon thyme. Transfer the soufflé base to a large bowl, press a piece of plastic wrap directly on the surface and let cool.
Preheat the oven to 375°. Whisk the soufflé base until smooth, then fold in the crabmeat. Season with salt and pepper.
Beat the egg whites until they hold firm peaks. Stir one-third of the beaten whites into the base to lighten it, then fold in the remaining whites. Spoon the batter into the ramekins, filling them to within 1/2 inch of the rims. Wipe the rims clean.
Pour enough hot water into the roasting pan to reach halfway up the sides of the ramekins. Bake the soufflés for 30 minutes, or until lightly browned. Serve immediately with the Chervil Butter Sauce.