My sweet potatoes soup with lentil

Sweet potatoes are renowned for being the healthiest vegetable you can eat. They  are packed with complex carbohydrates, dietary fiber, beta carotene, vitamin C, and vitamin B6. Aside from being extremely good for you, they are also very delicious. As a kid, we reserved sweet potatoes for the holidays, but because of their superior nutritional value, I have since incorporated them into my employer's everyday meals. We eat them in many recipes. When the weather gets cooler though, I prefer to enjoy sweet potatoes in this rich and creamy soup. This recipe is perfect for a cool autumn day, and it could not be simpler to make either. It contains just 6 ingredients, sweet potatoes, onions, celery, poultry seasoning, stock, milk or cream and water. You could even omit the milk or cream to have a lower fat version of this recipe with just 5 ingredients.
Sweet Potato Soup 

Ingredients
6 large sweet potatoes, peeled and chopped in similarly sized pieces
1 large onion, roughly chopped
3 ribs of celery, roughly chopped
2 teaspoons poultry seasoning
1 quart chicken or vegetable stock
1 quart water, or enough additional water to just cover vegetables
2 cups milk or cream
1/4 cup lentil
Method
1. Add all chopped vegetables to a large soup pot. Add poultry seasoning. Add stock. Add just enough water until all vegetables are just covered. You may have to add a little more water to cover the vegetables. Boil until vegetables are very tender.
2. Use a submersible blender to puree the soup, or you can also add the vegetables and stock to a blender and puree in batches.