Heat olive oil in a large pot or Dutch oven over medium heat. Add onion and cook until softened, about 5-6 minutes. Add garlic and cook for another 30 seconds until fragrant.

Pour in vegetable stock, add cauliflower, salt, turmeric, cumin, and red pepper flakes. Bring to a boil, then reduce heat, cover, and simmer for 10 minutes, or until cauliflower is tender.

Using an immersion blender or a regular blender (in batches), blend the soup until creamy. Stir in butter.

Serve warm, garnished with chopped parsley.