Preheat oven to 400 (200C) degrees, with one oven rack in the center and one rack under it.
Slice the squash into 1 1/2-inch chunks (if you're not using already prepared squash). Arrange in one layer on a large rimmed baking sheet. Sprinkle lightly with salt and grind black pepper over to taste. Scatter the bacon over the squash.
Place a large oven-proof saute pan or Dutch oven over medium heat. Add the butter and olive oil. When the butter is melted, stir in the leek and shallot or onion. Cook until softened and translucent, about 5 minutes. Stir in the rice and cook another minute, stirring to coat the grains with the oil.
Pour in the wine and let it bubble for 30 seconds, then turn off the heat. Add the stock, Parmesan rind (if you have one) and 1 teaspoon salt.
Slide the sheet pan on the lower rack and the saute pan on the middle rack. Bake the rice and squash 30-35 minutes. To check if it's done, the rice should be very tender and not completely absorbed into the broth. The squash should be tender and the bacon rendered and deep brown.
Use a slotted spoon or spatula to transfer the squash and bacon to the risotto pan, leaving the excess fat behind. Sprinkle the kale and cheese over, and gently stir, folding into the risotto until everything is evenly mixed.
Serve right away while it's hot!
Take this dish up a notch with this cheffy touch: Drizzle the risotto with good balsamic vinegar and a pinch of crushed red chili flakes before serving.
To make this vegetarian, skip the bacon. Toss the squash with 2-3 tablespoons extra virgin olive oil along with the seasonings before roasting.