Begin by pre heating your oven to 350 degrees F
Oil a deep 9x13 baking dish
Set a large pot of water to boil on your stovetop
Once the water is at a rolling boil pour in
4 Cups uncooked macaroni noodles
Remove when noodles are al dente, drain and set aside
Set a 12 inch skillet on medium heat and add
2 Tablespoons butter
2 Tablespoons flour
Whisk together until thick, then add
1/2 Cup whole milk
1 Cup chicken broth
Continue whisking
While continuing to whisk, add in
2 Cups shredded cheese
1 Cup yellow onion, chopped
1/2 Cup sour cream
3 cups diced, cooked ham
The cooked noodles
Once the mixture is warmed through and combined, pour it into the prepared baking dish
Over the top of the ham and noodle mixture sprinkle
1/2 Cup crushed croutons
Bake in the preheated oven until the casserole is bubbling and the bread crumbs have browned, about 40 minutes