Rinse cauliflower and dry very well. Cut into small bite sized pieces, about ½-inch.
Melt butter and mix with poultry seasoning, parsley, rosemary salt and pepper.
Toss the butter mixture with cauliflower, onion, mushrooms, and celery.
Place on a rimmed baking sheet and roast 15 minutes. Stir and roast an additional 18-23 minutes or until golden and tender.
Serve warm.
Notes
Refrigerate leftovers in an airtight container for 3-5 days.
To freeze, simply prepare stuffing and cool it completely. Store in an airtight freezer-safe container or bag to maintain its quality for 10-12 months. Thaw stuffing in the refrigerator before reheating.
Reheat stuffing in the oven at 350°F until heated through.