Preheat oven to 400°F (200°C). Cut acorn squash in half, scoop out seeds, and brush with olive oil.
Roast squash cut-side down for 35–40 minutes until soft. Let it cool slightly.
Sauté onion and garlic in a pan with olive oil until soft and fragrant.
Scoop roasted squash into a blender along with onion mixture, broth, and almond milk.
Blend until smooth. Seriously smooth—no chunks allowed.
Return sauce to pan, add seasoning, and simmer for 10 minutes.
Taste and adjust. Add salt, pepper, or broth as needed.
