Preheat oven to 450°F
Cut the stem off of each butternut squash and slice in half longways. Scoop out seeds. Optional: reserve seeds to make toasted squash seeds.
Lightly oil flesh side of squash. Place 2 unpeeled garlic cloves in the hollow of each squash where the seeds were.
Place squash hollow-side down onto baking sheet. Bake for 45 minutes or until the skin side turns slightly brown and a fork passes easily through the thickest part of the squash. Set aside to cool.
Roughly chop onion and sauté in a small amount of cooking oil until it starts to turn clear.
Once the roasted squash is cool, scoop the flesh out of skin and reserve. Peel roasted garlic cloves. Discard squash skin and garlic paper.
Place squash, peeled garlic cloves, and sautéed onion in blender. Add water to the level of the squash and puree.
Pour puree into a soup pot. Warm over medium-low heat. Use a lid while warming the soup as it tends to splatter. Season with salt and pepper to taste.
Optional: Serve with roasted squash seeds, fresh parsley, and creme fraiche.