In a small saucepan, melt the 1/4 c butter and then whisk in the flour.
Cook this over medium heat for just a minute.
Whisk in the chicken broth and milk. Cook and stir until it begins to boil. Remove from heat.
In a large bowl, combine all the rest of the other ingredients. (I like to reserve a handful of the shredded cheese to sprinkle on top before baking. This is optional.)
Stir in the chicken broth mixture.
Combine it all and then spread it into a greased (or sprayed with cooking spray) 9x13 baking dish.
Sprinkle with the reserved cheese, if you didn't mix it all in.
Bake for 45 minutes, or until it is just starting to get golden on top and the potatoes are cooked through.