Slice off the asparagus tips about 2" from the end. Cut them into 1/2" pieces and reserve them. Cut the remaining stalks into 1" pieces.
Heat the oil in a saucepan over medium heat. Add the leeks and cook for 5 minutes, or until soft. Add 1 1/2 cups of the stock, broth or water. Stir in the dill if using and sliced asparagus. Cook for 8 minutes. Add the garlic and cook for 2 minutes, or until the asparagus is tender.
Remove from the heat and add the remaining 1/2 cup stock, broth or water. Pour into a blender, 2 cups at a time, and process until pureed. Return to the pot, add the reserved asparagus tips, and cook for 1 minute, or until hot throughout.
Divide among 4 bowls. Top each portion with the nutmeg.