Heat the butter and olive oil in a skillet over medium heat. Stir in the butternut squash, turnips, celery, onion, and garlic; cook and stir until the vegetables just begin to brown, about 10 minutes. Meanwhile, heat the chicken stock in a large pot over medium heat until simmering.
Transfer the vegetables to simmering stock, and add the bay leaf, honey, pepper, nutmeg, coriander, cayenne pepper, and salt. Continue simmering until all the vegetables are softened, about 20 minutes. Remove the bay leaf before serving.