1Preheat the oven. Place cauliflower florets, halved onion, and whole garlic head on a baking sheet. Add salt and olive oil, toss to coat and spread the vegetables in a single layer.
2Roast vegetables in the preheated oven until tender and slightly browned.
3Add roasted potatoes, onion, cauliflower, and garlic to a blender.
4Add vegetable broth to the blender.
5Blend the mixture until smooth.
6Heat blended soup in a pot over medium heat.
7Stir in oat cream until smooth and creamy.
8Serve the soup in bowls.
9Top with oat cream, parsley, and a drizzle of oil.
10Garnish with roasted cauliflower florets and serve with toasted bread.