Cut cauliflower into florets and gently steam for 15 minutes or until just fork-tender (but not over cooked). Transfer to a food processor or strong blender with remaining ingredients. Allow motor to run until its smooth and creamy like mashed potatoes, stopping periodically as needed to scrape the sides and break apart large chunks. Also add more non-dairy milk if necessary to get the mixture to fully incorporate (you may need more with a blender than a food processor). Once fully incorporated, smooth and creamy taste; adding more onion or garlic powder as desired plus salt and pepper to taste.