In large pot, cook onions in butter over medium heat until softened, about 5 minutes. Add squash, apples, garlic, broth, 1 cup (250 mL) of water, thyme, salt and pepper; bring to boil. Reduce heat, cover and simmer for about 20 minutes or until squash is tender. Let cool slightly. Purée soup in blender until smooth. Return to pot and stir in maple syrup and nutmeg. Reheat soup until hot. Serve garnished with pumpkin seeds.