Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish with cooking spray or a bit of butter.
Layer the chicken evenly in the bottom of the baking dish. If you’re using rotisserie chicken, just pull it into bite-sized pieces and scatter it in an even layer.
Shredded chicken spread in a greased baking dish
Shredded chicken spread in a greased baking dish
Arrange the sliced ham over the chicken. You can cut the ham into strips or squares so it spreads more evenly—no need to be precise, just make sure most of the chicken is covered.
Layer the Swiss cheese over the ham. If you’re using slices, overlap them slightly so you get a good cheesy layer. If using shredded Swiss, sprinkle it evenly over the top.
In a medium bowl, whisk together the milk, chicken broth, sour cream, condensed cream of chicken soup, Dijon mustard, garlic powder, onion powder, dried thyme (if using), salt, and pepper until smooth and well combined.
Creamy casserole sauce being whisked in a mixing bowl
Creamy casserole sauce being whisked in a mixing bowl
Pour the sauce mixture evenly over the chicken, ham, and cheese layers, making sure it seeps into the corners of the dish.
In a separate small bowl, stir together the panko breadcrumbs, melted butter, and grated Parmesan cheese until the crumbs are evenly coated and look like wet sand.
Sprinkle the buttery breadcrumb mixture evenly over the top of the casserole to form a crunchy topping.
Breadcrumb topping scattered over an unbaked casserole
Breadcrumb topping scattered over an unbaked casserole
Cover the baking dish loosely with foil and bake for 20 minutes. This helps everything heat through without over-browning the top.
Remove the foil and bake for an additional 15–20 minutes, or until the casserole is bubbling around the edges and the topping is golden brown.
Let the casserole rest for about 5–10 minutes before serving. This helps it set up a bit and makes it easier to scoop. Garnish with chopped fresh parsley if you like, then serve warm.
Variations & Tips
To make this recipe work for your week, there are a few easy tweaks you can try. For a lighter version, swap the sour cream for plain Greek yogurt and use reduced-fat Swiss cheese; you can also use low-fat condensed soup and skim or 1% milk.
If you prefer a from-scratch sauce, skip the condensed soup and whisk 3 tablespoons butter and 3 tablespoons flour together in a saucepan, then slowly add the milk and broth, cooking until thickened before seasoning and using as directed.
