1. In a soup pot, heat the olive oil over medium-high heat. Add the onion and curry powder and cook 3 minutes. Add the butternut squash, apples, thyme, white beans, salt and vegetable broth and the 2 cups of water; bring to a boil. Reduce heat and cook until squash is very tender, about 15 minutes.
2. Working in batches, puree the soup in a food processor or blender until almost smooth.
3. Preheat the oven to 350 degrees and coat a baking sheet with cooking spray. Lightly spread each slice of bread with the mustard and top with 1 slice of the cheese. Toast in oven until cheese melts, about 7 minutes. Serve each bowl of soup with 1 piece of the toast.