Warm the oil in a heavy soup pot over medium high heat. Sauté onions with a pinch of salt and pepper in the oil until translucent, about 8 minutes. Add the garlic and sauté until aromatic, about a minute longer. Add the butternut squash and apple, then the curry powder, powdered ginger, ground mustard, white pepper, sage, cinnamon, nutmeg, and fresh ginger. Saute for 1 minute, until fragrant. Stir in the coconut milk and a dash of salt and pepper. Add the apple juice concentrate and water, and bring the soup to a boil, skimming any foam that rises. Reduce to medium, and simmer until vegetables are tender. Remove from heat, and puree soup with immersion blender, or in a blender or food processor. Stir in the lime juice. Taste and adjust seasoning.