You can use any macaroni and cheese recipe that you like. The link to my recipe for Macaroni and Cheese is here for you to follow. That recipe also provides a link to making a bechemel sauce. All you have to do in addition is layer in some left over chicken.
When all is said and done and you pull this out of the oven with the crispy top macaroni, and the cheese is all bubbly, serve your family up a big plate or bowl of this. The chicken stays moist and tender and what a great flavor you get in every bite from the chicken, the cheese sauce and the tomatoes.