Found this in my grandmother's recipe box labeled 'for special occasions' and now I understand why she made it every Easter for 40 years.

This oven baked 4-ingredient chicken cordon bleu casserole is exactly the kind of dish I can picture my grandmother pulling out every Easter: simple, comforting, and just fancy enough to feel special. The recipe is built on the classic flavors of chicken cordon bleu—tender chicken, salty ham, and melty Swiss cheese—baked together in a creamy sauce until bubbly and golden on top. It uses only four main ingredients (plus basic pantry seasonings) and comes together in one glass baking dish, which makes it perfect for holidays, church potlucks, or any Sunday dinner when you want something that feels like it came from a well-loved recipe box.

Serve this casserole hot, scooped straight from the baking dish with a wooden spoon so you get all those layers of chicken, ham, cheese, and creamy sauce in each portion. It pairs wonderfully with buttered egg noodles, mashed potatoes, or rice to soak up the extra sauce. Add a simple green side like steamed green beans, roasted asparagus, or a tossed salad with a light vinaigrette to balance the richness. Warm dinner rolls or a sliced baguette are always welcome for mopping up the cheesy, creamy goodness.

Servings: 6

2 pounds boneless, skinless chicken breasts, cut into bite-size pieces

1/2 cup milk (any kind, to thin the soup slightly)

1/2 teaspoon salt (or to taste, depending on how salty your ham is)

Preheat your oven to 375°F (190°C). Lightly grease a 9x13-inch glass baking dish with butter or cooking spray. Using glass helps you see those golden edges and gives that homey, old-fashioned look.

Prep the chicken by trimming any excess fat from the boneless, skinless chicken breasts. Cut the chicken into bite-size pieces, about 1-inch cubes, so they cook evenly and stay tender. Pat them dry with paper towels to help them brown a bit in the oven.

Season the chicken pieces in a medium bowl with the salt, black pepper, garlic powder, onion powder, and dried thyme or parsley if using. Toss well so every piece is lightly coated with the seasonings.

Spread the seasoned chicken evenly in the bottom of the greased 9x13-inch glass baking dish, making a single layer as much as possible. It’s fine if a few pieces overlap, but try not to pile them too high in one spot.

Layer the ham over the chicken. If your ham is in slices, stack a few slices at a time and cut them into strips or squares. Scatter the ham evenly over the chicken so every bite has a little bit of that salty, smoky flavor.

Arrange the Swiss cheese over the ham. Lay the slices in a single layer, slightly overlapping if needed, to cover the top. If you’re using shredded Swiss, sprinkle it evenly over the ham so you have a good cheese blanket. This is what will melt and get those gooey, stretchy pockets of cheese when you scoop it out.

In a separate bowl or large measuring cup, whisk together the condensed cream of chicken soup and the milk until smooth and pourable. It should be thick but not gloppy, like a rich sauce. Taste and adjust with a pinch more pepper or herbs if you like.

Pour the soup mixture slowly over the cheese-topped casserole, trying to cover as much of the surface as possible. Use a spatula or the back of a spoon to gently nudge the sauce into the corners and along the edges so it seeps down between the layers. Don’t stir; you want to keep the layers of chicken, ham, and cheese intact.

Cover the baking dish tightly with foil. Bake in the preheated 375°F (190°C) oven for 30 minutes. This helps the chicken cook through gently and keeps everything moist.

After 30 minutes, carefully remove the foil (watch for steam). Return the uncovered casserole to the oven and bake for another 15–20 minutes, or until the sauce is bubbling around the edges, the cheese is fully melted, and the top is lightly golden in spots.

Check for doneness by cutting into the thickest part of the chicken layer with a fork. The chicken pieces should be white all the way through with no pink, and the juices should run clear. If needed, bake an additional 5–10 minutes, checking again.

Once done, remove the casserole from the oven and let it rest for about 5–10 minutes. This short rest helps the layers settle a bit so it scoops out more neatly and keeps little mouths from getting burned.

To serve, use a wooden spoon to scoop generous portions, making sure you dig all the way down to get some of the creamy sauce, chicken, ham, and melted Swiss in each serving. Enjoy hot with your favorite sides.

For picky eaters, you can swap the Swiss cheese for a milder cheese like mozzarella or Monterey Jack, or do half Swiss and half mozzarella to ease them into the stronger flavor. If someone in the family isn’t a fan of ham, use turkey or thinly sliced deli chicken instead, or leave a corner of the casserole ham-free and mark it with a toothpick so everyone knows which side is which. For a slightly fancier holiday version, sprinkle 1/2 cup of seasoned breadcrumbs over the top after you remove the foil and bake uncovered until the crumbs are golden and crisp. You can also stir 1–2 teaspoons of Dijon mustard into the soup and milk mixture for a more traditional chicken cordon bleu flavor. If you want to add a vegetable right into the dish, scatter a cup of thawed frozen peas or small broccoli florets over the chicken before adding the ham, keeping in mind this will add a bit of moisture and may need a few extra minutes of baking time. For a lighter version, use reduced-sodium ham, low-sodium condensed soup, and 2% Swiss cheese, and consider using evaporated skim milk in place of regular milk. Food safety tips: Always wash your hands, cutting board, and knife thoroughly after handling raw chicken, and keep raw chicken separate from other ingredients. Make sure the chicken reaches an internal temperature of 165°F (74°C) in the thickest pieces before serving; if you’re unsure, use an instant-read thermometer to check. Leftovers should be cooled slightly, then stored in an airtight container in the refrigerator within 2 hours and eaten within 3–4 days. Reheat leftovers until they are steaming hot all the way through; if reheating in the oven, cover the dish with foil so it doesn’t dry out. If you choose to freeze leftovers, cool completely, wrap well, and freeze for up to 2–3 months; thaw overnight in the refrigerator before reheating.