Frothy Lettuce Soup with Onion Custard - salt

Method

• Bring a large saucepan of water to a boil.
• Add 2 tablespoons of salt and the heads of lettuce and blanch, stirring gently with a wire skimmer, for 3 minutes.
• Drain the lettuce and rinse under cold water.
• Lightly squeeze out excess water.
• Transfer the lettuce, still wet, to a blender and puree until smooth.
• Scrape into a bowl.
• In a small skillet, cook the bacon over moderate heat until lightly browned, about 4 minutes.
• In a large skillet, combine 2 tablespoons of the butter with the onion.
• Cover and cook over low heat, stirring often, until softened, about 15 minutes.
• Transfer the onion to a blender.
• Add 1/4 cup of the chicken stock and puree.
• In a medium bowl, whisk the egg, then whisk in the milk and onion puree.
• Season with 1/2 teaspoon of salt, 1/8 teaspoon of pepper and the nutmeg.
• Butter four 8-ounce coffee mugs or large ramekins.
• Pour the onion mixture into the mugs and cover with plastic wrap.
• Set a round rack in a large, wide pot.
• Add enough water to reach just under the rack without touching it and bring to a boil.
• Set the mugs on the rack.
• Cover and steam over low heat until the onion custards are barely set, about 22 minutes.
• Meanwhile, in a medium saucepan, bring the remaining 1 cup of stock to a boil.
• Whisk in the lettuce puree and simmer over moderate heat for 3 minutes.
• Whisk in the creme fraiche and simmer for 3 minutes.
• Remove from the heat and gradually whisk in the remaining 3 tablespoons of butter.
• Season with salt and pepper.
• Finely shred the reserved 2 lettuce leaves.
• When the custards are done, discard the plastic wrap.
• Scatter the bacon and shredded lettuce over the top.
• Serve the custards and pour in the lettuce soup at the table.