Heat a larger saucepan with oil on medium-high, add onion and cook until soft, about 3 minutes. Stir in garlic, celery, green onion, thyme, parsley and cook until fragrant, about 1 minute.
Add cauliflower florets, vegetable broth, allspice berries/pimento, pepper, and salt. Bring soup to a boil, cover and reduce to simmer until cauliflower is fork tender, about 15-20 minutes. Remove Scotch bonnet pepper.
Allow soup to cool slightly, transfer soup to a high-speed blender, carefully process until smooth. You can do it in batches to avoid blender bowl overflowing. If using an immersion blender, Serve soup and enjoy.