Leek and Potato soup

I bought two turkey legs this week.  I've never done that before.  I thought I'd get creative with a new protein source since I've been pondering protein lately.  I've purchased turkey breasts before but I thought I'd give a go with the richer taste of the leg meat.  I used the leg meat to make 'turkey fingers' which I might get around to posting a recipe for since they were a huge hit with Daughter.  I then threw the rest into a my enameled cast iron pot, filled it with water, and simmered it for a few hours.  Once it cooled down I put the whole pot into the fridge and last night took it out to make some soup.  I am pleased with the result.  I can't wait to share this with my mom when she visits from Newfoundland next week....I popped some directly into the freezer for her.

Leek and Potato Soup
1 Leek, sliced
3 large white potatoes, chopped into large pieces, remove blemished skin
about 6 cups Turkey stock, with leftover meat taken off the bones - about 1/2 cup
1/2 tsp mustard powder and/or prepared mustard (I used some yummy honey tarragon mustard)
1 tsp oregano
1 tsp sage
2 tbsp tahini (adjustable and optional)
Salt/Pepper to taste

Fry the leeks in a large stock pot over medium-high in a small bit of oil until lightly browned.  Add remaining ingredients (except the tahini).  Heat until boiling and then reduce heat to a low simmer and cook until potatoes are falling apart.  Add the tahini for a creamy taste, I usually wait until it is almost done before adding so I can adjust the amount accordingly (add 1 tbsp or less at time and taste the result).