Preheat oven to 350° degrees.
Cut squash in half.
Scoop out the seeds.
Spread butter on the squash.
Place the squash in a sheet pan and cover with a foil.
Bake the squash for approximately 45 minutes to an hour, until golden brown and soft.
Take the squash out of the oven and let cool.
Scoop out the pulp and discard the skin.
Place the squash in a bowl.
Sauté onions and chile chipotle, then add it to the butternut squash.
Mash everything to a smooth consistency.