Makes 6 to 8 servings
This recipe makes enough for 6 to 8 people as part of a bigger spread, but can be easily doubled, if needed. We used pancetta, but you can leave it out for a hearty vegetarian option.
- Preheat the oven to 350°F.
- Heat a large skillet over medium-high heat. Add the pancetta and cook, stirring occasionally, until the fat has rendered and the pancetta is browned and crisp, about 8 minutes. Use a slotted spoon to transfer the pancetta to a plate.
- To the same pan, add the mushrooms and a pinch of salt. Cook, stirring occasionally, until the mushrooms are golden brown, about 12 minutes. Add the leeks and cook until soft, about 6 minutes.
- Deglaze the pan with white wine and remove from the heat.
- In a large bowl, combine the bread, cooked mushroom mixture, and about 3/4 of the Gruyere. In a separate bowl, whisk together the eggs and milk, and pour over the other ingredients. Toss to combine.
- Transfer the mixture and any remaining liquid to a medium-sized baking dish. Cover with foil and bake for 30 minutes. Remove the foil, sprinkle with the remaining cheese, and bake, uncovered, until the cheese has melted and the top layer of bread begins to brown around the edges, about 10 minutes more.