Heat the oil in a large soup pot over a medium-high heat. Add the onion and carrot and cook until they begin to soften, stirring occasionally, about 6 minutes. Add the garlic and cook for 1 minute more. Add the butternut squash, all spice, salt and cayenne and stir to combine. Add the thyme, broth, and tomatoes with their juice. Bring to a boil then reduce heat, cover and simmer for 10 minutes. Add the kale and the chickpeas, if using, and cook for 10 minutes more until the squash is tender and the kale has wilted. Pick out the thyme springs and discard before serving.