Tender acorn squash is filled with an Italian sausage stuffing in this simple main or side dish that's perfect for weeknight meals and holiday dinners alike.
Prepare the squash. Preheat the oven to 425°F and place a rimmed baking sheet in the oven to preheat. Cut ½” from the pointy end of the squash to help each half stand straight. Halve each through the center, then scoop out the seeds and discard. Brush the cut sides of the squash with the 1 tablespoon olive oil and sprinkle with ¼ teaspoon salt and ¼ teaspoon pepper.
Roast the squash. Place the halves cut-side-down on the hot baking sheet and roast for 25-30 minutes, or until tender when poked with a fork or paring knife, remove from the oven, tent loosely with foil, and set aside.
Meanwhile, cook the sausage and veggies. In a 10-inch skillet, cook ½ pound ground sausage on medium-high until cooked through, about 5-8 minutes. Add ½ pound sliced mushrooms, 2 diced celery stalks, 1 diced small yellow onion, ¾ cup slivered kale, and ½ diced yellow bell pepper. Season with ¾ teaspoon kosher salt and ¾ teaspoon ground black pepper and cook until the vegetables are tender, about 5 minutes. Transfer the mixture to a large bowl.
Add the savory ingredients to the filling. Stir in 3 cups dried bread cubes, ½ cup shredded Gouda cheese, ½ cup grated Parmesan cheese, and ¼ cup toasted pine nuts. Add ¼ cup chicken broth and stir to combine. Add more chicken broth if the stuffing seems dry but not so much it’s mushy.
Stuff the squash halves with the sausage mixture. Divide the stuffing among the squash halves and top each half with the remaining shredded gouda. Bake for 20-25 minutes or until the stuffing is warmed through and the cheese is melted. Serve with more Parmesan cheese if desired.