• Preheat the oven to 350°F. Butter two 9x13-inch baking dishes. 

MAKE THE CORNBREAD:

• In a large bowl, combine flour, cornmeal, sugar, baking powder and 1/2 teaspoon salt. Stir in 1 1/4 cups milk, 2 eggs, and melted butter. Pour the batter into a buttered baking dish and bake until a toothpick inserted in the center comes out clean, 30 to 35 minutes. Let cool and then cut cornbread into bite-size pieces.

PREPARE THE DRESSING:

• Meanwhile, in a small bowl, soak the porcini mushrooms in 1 1/4 cups hot water for 15 minutes. With a slotted spoon, transfer the mushrooms to a cutting board and roughly chop. Save the chopped mushrooms AND their soaking liquid.
• Melt 1/4 cup butter in a large frying pan over medium-high heat. Add the leeks, garlic, shallots, porcini, sage and salt. Cook, stirring, until the leeks and shallots are soft, about 5 minutes. Carefully pour in the porcini liquid, leaving behind any grit at the bottom of the bowl.
• In a very large bowl, whisk together remaining 4 cups of milk and 6 eggs. Stir in the  leek mixture. Add the baguette cubes and stir. Add the cornbread cubes and fold gently to mix. Transfer to the second buttered baking dish and scatter the gorgonzola crumbles over the top. Bake until set, about 40 minutes. Let sit 5 to 10 minutes before serving.