Preheat oven to 425℉.
On a rimmed baking sheet, spread out cauliflower florets evenly. Drizzle 1½ tablespoons olive oil over cauliflower and sprinkle ¼ teaspoon salt and ⅛ teaspoon black pepper over the top. Mix up cauliflower until evenly coated with oil.
Roast for 25 minutes, tossing pan halfway through roasting time. Then set aside 4-6 florets for garnishing soup.
In a large pot, heat 1 tablespoon olive oil over medium heat. Add chopped red onion and cook for 5-7 minutes until softened. Add garlic and cook for another minute.
Add chicken broth to pot along with potatoes, corn, Creole seasoning, ¼ teaspoon salt, and ⅛ teaspoon black pepper.
Bring pot to a boil, reduce heat, and simmer for 20 minutes. Add zucchini while simmering.
Meanwhile, cauliflower will finish roasting and it is time to add florets and ½ n ½ to a blender. Blend until mixture is smooth and creamy.
Add cauliflower mixture to pot and continue to cook until warmed through, about 5 minutes.
Add parsley, thyme, and dill and stir.
When serving, top with roasted floret and a pinch of fresh parsley if desired.