2. Add the remaining butter to the same pan over medium heat. Add the leeks, season with salt and cook, stirring, until the leeks are wilted but not brown. Return the mushroom mixture to the pan, stir and remove pan from heat. In a large bowl whisk the eggs, milk and cream together until well-blended Add the cayenne and season well with salt and pepper. Whisk again, then stir in the Gruyère.
3. Butter the bottom and sides of an 8-inch square baking dish. Spread a thin layer of the mushroom and leek mixture on the bottom. Add the bread, then spread the remaining mushroom mixture on top. Pour the egg mixture into the dish, taking care that the cheese is evenly distributed. Press down lightly on the bread to be sure it is well-moistened. Cover and set aside 2 hours or refrigerate for a longer time, up to overnight.
4. Allow the pudding to come to room temperature a good 30 minutes before baking. Heat the oven to 350 degrees. Uncover the pudding, press down on the bread again, then dust with the Parmigiano-Reggiano. Bake 35 to 40 minutes until set and lightly browned. Let sit a few minutes, then scatter with sage leaves before serving.
Babka Bread Pudding
Time: 20 minutes plus up to 12 hours soaking and baking
Yield: 6 servings
3 large eggs
⅓ cup plus 1 ½ tablespoons sugar
2 tablespoons honey
1 cup whole milk
1 cup half-and-half
1 teaspoon vanilla extract
¼ teaspoon salt
½ cup raisins (optional)
5 cups cubed babka; brioche, challah, panettone or other bread can be used
Unsalted butter for baking dish
½ teaspoon cinnamon
Whipped cream or ice cream for serving
1. In a large bowl whisk eggs until well blended. Whisk in the ⅓ cup sugar and the honey until dissolved. Whisk in the milk, half-and-half, vanilla and salt. Stir in the raisins if using. Add the bread, pressing down on it so it sops up the liquid.