Preheat oven to 450 degrees.
Halve squash lengthwise.
Scoop out and discard seeds.
On a rimmed baking sheet place the squash, cut side down, add an inch of water and cover tightly with aluminum foil.
Roast until almost tender and easily pierced with a knife, about 15 to 25 minutes. When cool enough to handle, scrape out flesh and discard the skin.
Cook the bacon in a large skillet over medium heat, until crisp, 4 to 5 minutes.
Transfer bacon to a paper-towel-lined plate; set aside.
Add the onion to fat in the pan, and cook until softened, 4 to 5 minutes.
Add kale; cook until soft, 3 to 4 minutes.
In a blender add the squash and 1 cup of water and puree until smooth. (Start with one cup adding more or less as necessary to achieve desired consistency)
Add the squash to the onion and kale mixture and bring to a boil.
Season generously with salt and pepper.
Serve, garnished with bacon.