Preheat the oven to 375 degrees F. Grease a shallow 9?13-inch casserole dish or similar 3-quart baking dish with non-stick cooking spray.

Heat 1 tablespoon of olive oil in a large skillet or Dutch oven over medium heat. Add half of the butternut squash, ? tablespoon of thyme, ? teaspoon salt, and 1/8 teaspoon pepper. Saut? until the squash is beginning to brown, about 3 minutes.

Add half of the kale, half of the onions, and half of the garlic to the skillet. Cook until the kale and onions begin to soften, about 4 minutes.

Add 1/2 cup of the stock, stir, and let cook for 1 minute to reduce slightly. Transfer the mixture to the prepared baking dish and spread it into an even layer.

Heat the remaining tablespoon of olive oil in the skillet. Repeat steps 2 to 4 with the remaining ingredients, transferring the mixture to the casserole dish. Cover with aluminum foil and bake for 30 to 35 minutes or until the squash is soft when pierced with a knife.

While the squash bakes, prepare the topping: In a small bowl, combine the breadcrumbs, Parmesan, sage, nutmeg, and salt. Pour the melted butter over the top and stir to combine.

Remove the casserole from the oven, remove the foil, and sprinkle the breadcrumb mixture evenly over the top. Reduce the oven temperature to 350 degrees F and bake uncovered until the breadcrumbs are golden, about 20 minutes. Serve warm.