Buttermilk Pumpkin Mac N Cheese

This is hands down the daycare favorite meal.  Creamy Pumpkin Mac and Cheese made with lowfat buttermilk.  It's tangy and filling, and full of vitamin A. According to Libby's webpage:  http://www.myfitnesspal.com/food/calories/libbys-pure-pumpkin-15-oz-can-22647796
a 4 oz serving of pumpkin only has forty calories, and provides 300 % of the vitamin A needed in a day. 
 I have a three year old, two year old and a one year old baby, and they all cleaned their plates! 

Buttermilk Pumpkin Mac N Cheese
1 box short cut pasta, like macaroni (I only had penne, but it works great too) cooked and drained
3 T butter
3 T flour
salt and pepper
3 C buttermilk
1 tsp grill seasoning
pinch of ground nutmeg
4 C grated sharp cheddar cheese
1 15 oz can libby pumpkin (make sure it's not pie filling)

In the pot you boiled the pasta in, melt the butter and add the flour.  It should foam and start to smell nutty.  You are building a bechamel sauce.  Add the buttermilk in small increments, whisking to encorporate and avoid lumps.  Let the sauce come to a bubble under medium high heat while you whisk, and then add more buttermilk, let it return to a bubble, etc... until all of it is used.  It should resemble a medium bodied gravy.  It will thicken when you add the cheese and pumpkin.  Season and then add the shredded cheese.  Stir well until cheese is melted.  Finally, add the pumpkin and stir well to encorporate.