In a 5- to 6-quart pan over medium-high heat, frequently stir onions, apples, carrots, raisins, garlic, and butter until onions are limp, 10 to 12 minutes.
Add curry powder and flour and stir to mix well.
Stir in broth. Stir over high heat until boiling, then reduce heat and simmer, stirring occasionally, until carrots are very tender to bite, about 20 minutes.
In a blender, whirl soup, a portion at a time, until very smooth. Return to pan. Add cream and stir often over medium heat until hot, 4 to 5 minutes.
Ladle into bowls and add salt, pepper, and chutney to taste.