Step 1

Preheat the oven to 350˚F and butter a 9-by-13-inch baking dish. Bring a large pot of salted water to a boil. Add the spaghetti and cook 2 minutes less than the package directs. Reserve ½ cup cooking water, then drain.

Step 2

Heat 2 tablespoons butter in a large Dutch oven over medium-high heat. Add the mushrooms and ½ teaspoon salt and sauté until the mushrooms begin to turn golden, 5 to 7 minutes.

Step 3

Stir in the garlic and cook until fragrant, 1 minute. Sprinkle in the flour and cook, stirring, until toasted, 2 to 3 minutes. Add the wine and cook until reduced by half, 3 to 5 minutes. Slowly stir in the broth and cook until the sauce thickens, 7 to 9 minutes. Reduce the heat to medium-low. Gradually stir in the cream cheese, gouda, and ¾ cup parmesan until melted.

Step 4

Add the chicken, spaghetti, and peas to the sauce and stir. Add the reserved cooking water, about 2 tablespoons at a time, until very saucy.

Step 5

Melt the remaining 2 tablespoons butter in a bowl in the microwave. Stir in the panko, parsley, and the remaining ¼ cup parmesan.

Step 6

Pour the spaghetti mixture into the prepared baking dish and sprinkle with the panko mixture. Bake until bubbly and golden brown, about 25 minutes. Let rest about 5 minutes before serving.