Preheat oven to 180°C and line baking tray with parchment paper. Arrange the cauliflower florets in the prepared tray, drizzle with oil and season with spices. Bake for 15-20 minutes or until golden brown.
Make the avocado dressing. Place avocado, lemon juice, mustard powder, garlic, onion powder, Italian seasonings, milk, parsley, salt and pepper into a blender. Process until smooth and creamy. You can add more milk if needed.
Serve roasted cauliflower warm. Drizzle with avocado dressing and garnish with parsley. Enjoy!