How to Make It
Preheat the oven to 400°. On a large rimmed baking sheet, place the squash cut side up and rub the flesh all over with 1 tablespoon of the olive oil. Sprinkle generously with salt and pepper and roast for about 1 hour, until the squash is easily pierced with a knife. Let cool slightly, then scoop out the flesh into a large bowl, leaving the squash shells intact. Arrange the shells on the baking sheet and keep the oven hot.
Mince the garlic cloves and sprinkle with a pinch of salt. Use your knife to mash to a paste. In a large skillet, heat 3 tablespoons of the olive oil over moderate heat and add the garlic, stirring until just fragrant, about 30 seconds. Add the breadcrumbs and toast, stirring frequently, until crisp and golden, about 5 minutes. Transfer the crumbs to a medium bowl and stir in the cheese and herbs and season with salt and pepper. Wipe out the skillet.
In the same skillet, heat the remaining 1 tablespoon of the olive oil over moderate heat. Add the sausage and cook, breaking up any large pieces with a spoon, until just cooked through, 6 to 8 minutes.
Add the breadcrumbs, sausage and the kale to the squash and toss. Divide the mixture evenly among the four squash shells and drizzle generously with olive oil. Bake for about 20 minutes, until the filling is browned on top. Serve hot or warm.