Sauté onions in butter for about 5 minutes on medium-low heat. Stir in vegetables and cook for about 5 minutes. Add water to cover the vegetables. Add all spices, lentils, lemongrass, apples and hot pepper. Simmer for 20–30 minutes. Add coconut milk, vinegar, cilantro, parsley and green onions. Adjust salt to taste, let soup heat through and serve.