Heat olive oil in a saucepan. Add onion, sauté until translucent, about 5-6 minutes. Add garlic and cook 1 minute longer. Add cauliflower and vegetable broth. Bring to a boil. Cook until cauliflower is very tender, about 10-15 minutes.
Remove from heat and allow to cool slightly. Use an immersion blender or transfer cauliflower mixture to a blender. Blend until smooth.
Add the nutritional yeast, coconut milk, salt, and pepper. Taste and adjust the seasonings as needed.
Notes
Use canned coconut milk, specifically the creamy white part at the top of the can. This is what helps to create the creamy texture and rich flavor.
If you don’t have an immersion blender, portion the sauce into a food processor and puree it in intervals.
Adjust the texture of the alfredo by adding more coconut milk or vegetable broth to thin it out.