How to Make It
In a large saucepan, combine the clam broth, water and thyme and bring to a boil over moderately high heat. Add the potato and cook until almost tender when pierced, about 10 minutes.
Meanwhile, in a blender, beat the egg. With the machine on, gradually beat in the olive oil and then the lemon juice. Gradually add 1/2 cup of the hot clam broth and blend until emulsified. Season the sauce with salt and pepper.
Add the monkfish, peas, Serrano ham and piquillo pepper to the broth in the pot and cook for 2 1/2 minutes. Add the shrimp and simmer until they are pink and curled, about 2 minutes. Add the sherry. Remove the chowder from the heat and stir in the egg mixture. Season the soup with salt and pepper and serve.