Preparation

• Heat the oven to 375°F. In a medium skillet over medium heat, melt the butter with the water and a pinch of salt. Add the leeks and cook until tender, about 10 minutes. Set aside to cool. In a large bowl, whisk together the eggs and milk. Add the remaining ingredients, including the leeks, and gently toss them. The mixture should be well coated and somewhat soupy.
• Spread the mixture into a 4-quart soufflé dish, a 13×9-inch baking dish, or another ovenproof dish that’s at least 2 inches deep and big enough to hold the mixture. Put the dish on a baking sheet and bake until the top is crusty brown and a knife inserted in the middle comes out clean, 45 to 60 minutes. If the pudding looks too dark before it’s finished, cover with foil. Let cool slightly before serving.