Sausage-Stuffed Acorn Squash

Step 1
Preheat the oven to 375 degrees F (190 degrees C). Line a baking sheet with aluminum foil.

Step 2
Place squash halves, cut-side down, onto the prepared baking sheet.

Step 3
Bake in the preheated oven until tender, about 1 hour. Remove from the oven, turn squash halves over, and set aside to cool. Leave the oven on.

Step 4
Heat a large skillet over medium-high heat. Add sausage; cook and stir until browned and crumbly, 5 to 7 minutes; drain and discard grease. Add celery, mushrooms, and onion; cook and stir until celery is softened, 5 to 10 minutes. Remove from the heat.

Step 5
Beat egg in a large bowl; stir in sour cream and Parmesan cheese. Stir cheese mixture into sausage mixture, then spoon into squash halves.

Step 6
Return to the oven and bake until filling is cooked through, about 20 minutes.