Preparation Combine 2 cups water and 2 cups low-salt chicken broth in medium saucepan. Bring mixture just to simmer. Remove from heat. Add saffron threads. Cover and steep 20 minutes. Melt 3 tablespoons butter in heavy medium pot over medium-low heat. Add chopped onions and sauté until very tender but not brown, about 10 minutes. Add cauliflower pieces; stir to coat. Add saffron broth. Bring to simmer over high heat. Reduce heat, cover, and simmer until cauliflower pieces are tender, about 20 minutes. Working in batches, puree cauliflower mixture in food processor until smooth. Transfer cauliflower puree to large saucepan. Stir in half and half and bring to simmer. Season to taste with salt and pepper. (Can be made 1 day ahead. Cover and refrigerate. Bring to simmer before serving.) Ladle soup into bowls. Garnish with sliced fresh chives and serve.
Preparation Combine 2 cups water and 2 cups low-salt chicken broth in medium saucepan. Bring mixture just to simmer. Remove from heat. Add saffron threads. Cover and steep 20 minutes. Melt 3 tablespoons butter in heavy medium pot over medium-low heat. Add chopped onions and sauté until very tender but not brown, about 10 minutes. Add cauliflower pieces; stir to coat. Add saffron broth. Bring to simmer over high heat. Reduce heat, cover, and simmer until cauliflower pieces are tender, about 20 minutes. Working in batches, puree cauliflower mixture in food processor until smooth. Transfer cauliflower puree to large saucepan. Stir in half and half and bring to simmer. Season to taste with salt and pepper. (Can be made 1 day ahead. Cover and refrigerate. Bring to simmer before serving.) Ladle soup into bowls. Garnish with sliced fresh chives and serve.