1 (12 oz.) package pre-chopped fresh butternut squash
8 ounce cremini mushrooms, halved
1 cup frozen pearl onions, thawed
2 tablespoons extra-virgin olive oil
1 1/2 teaspoons kosher salt
1/4 teaspoon black pepper
1 (16 oz.) package potato gnocchi (such as Gia Russa)
2 tablespoons salted butter, softened
2 ounces Parmigiano-Reggiano cheese, shredded (about 1/2 cup), divided
Chopped fresh flat-leaf parsley
Toss together butternut squash, mushrooms, pearl onions, olive oil, salt, and pepper. Spoon vegetable mixture into a lightly greased 13- x 9-inch baking pan; place pan in oven. Preheat oven to 450°F, leaving pan in oven as it preheats. Bake vegetable mixture in preheated oven until squash is tender and browned, about 20 minutes.
Meanwhile, prepare gnocchi according to package directions, reserving 1 cup of the cooking water.
Remove vegetable mixture from oven. Stir in gnocchi and softened butter. (Be careful—the pan will be hot.) Gradually add up to 1 cup reserved cooking water, 1/4 cup at a time, stirring until a slightly thick sauce begins to form. Stir in 1/4 cup of the shredded cheese. Sprinkle top with remaining 1/4 cup cheese. Divide the vegetable and dumpling mixture evenly among 4 bowls. Garnish with chopped parsley, if desired, and serve immediately.