Saut the diced onion with butter in a large skillet or pot.
Add the veggies and cook until thawed.
Add in the cheese and stir until melted. Now add soups and milk or broth, seasonings, and diced chicken and sausage.
Continue to cook over low heat while you prepare the potatoes and preheat the oven.
Preheat the oven to 375 degrees. Spray a large casserole dish with cooking spray.
Peel potatoes and slice in thin rounds.
Layer the potatoes evenly over the bottom of the pan.
Sprinkle with salt and pepper.
Layer the meat and vegetable gravy evenly over the potatoes.
Cook for 1 hour, uncovered.
Check to see if the potatoes are cooked through by testing with a fork.
Add cheese evenly over the top. Then sprinkle with French fried onions or a tube of lightly crushed buttery crackers.
Cook for 10 minutes more.
Let cool for 10-15 minutes before serving.
