How to Make It
In a medium nonstick skillet, cook the chorizo over moderate heat, stirring occasionally, until crisp, about 6 minutes. Using a slotted spoon, transfer the chorizo to a plate lined with paper towels. Let cool slightly.
In a small saucepan, boil the beer over high heat until reduced to 1/2 cup, about 10 minutes. Add the cream and boil until reduced to 3/4 cup, about 12 minutes. Scrape into a bowl and let cool to room temperature, about 10 minutes. Stir in the cheese, egg yolks, Worcestershire sauce, mustard, chorizo and 3 tablespoons of the scallions. Season with 1 teaspoon of the salt and 1/4 teaspoon of the pepper. (The cheese will not melt.)
Preheat the broiler. Arrange the bread in a single layer on a large rimmed baking sheet. Broil about 4 inches from the heat until lightly browned, about 2 minutes. Carefully flip the toasts and spread each with about 1 tablespoon of the cheese mixture. Broil 4 inches from the heat for about 2 minutes, until the topping is bubbling and browned around the edges. Garnish with the remaining scallions and a sprinkle of salt before serving.