Mac and Cheese. (Freezeable)

Cook noodles for about 10 mins. Drain. Reserve liquid. Preheat oven to 400 degrees. In medium saucepan, melt butter. Blend in flour, mustard, s and p. Cook until smooth. Gradually add liquid. Then gradually mix in cheese that you have cut into blocks. Stir over low Heat until melted. Add pasta and mix together lightly. Pour into 2 qt. casserole. Bake until bubbly and begins to brown. Remove and let set 30 minutes before serving. When freezing, make sure noodles re totally covered. May need To add milk.