My grandmother served this at every ladies' luncheon in the 1960s. Three ingredients and it still tastes like pure elegance.

This oven baked 3-ingredient chicken duchess is exactly the kind of dish my grandmother would have served at every ladies' luncheon in the 1960s: comforting, pretty in the dish, and deceptively simple. It leans on a very mid-century combination—tender chicken, a velvety canned soup sauce, and piped mashed potatoes that bake up into golden, frilly peaks. With only three ingredients and one casserole dish, you get something that feels far more elegant than the effort involved, and it comes to the table looking like a little time capsule from the era of white gloves and coffee percolators.

Serve this chicken duchess hot from the oven with a crisp green salad dressed in a sharp vinaigrette to balance the richness, plus something bright and crunchy like steamed green beans or buttered peas. A simple basket of dinner rolls or a sliced baguette is perfect for soaking up the creamy sauce in the bottom of the casserole. For drinks, a dry white wine, a light rosé, or even iced tea with lemon keeps the whole meal feeling like a leisurely luncheon throwback.

Servings: 4

1 1/2 pounds boneless, skinless chicken breast or thigh pieces, cut into large bite-size chunks

Preheat your oven to 375°F (190°C). Lightly butter or spray a medium white oval casserole dish (about 2-quart capacity) so the chicken and potatoes release easily after baking.

Pat the chicken pieces dry with paper towels. This helps them bake more evenly and keeps excess moisture out of the sauce so it stays silky rather than watery.

Spoon the condensed cream of chicken soup into the prepared casserole dish. Spread it into an even layer with the back of a spoon, then add the chicken pieces on top, turning them gently so they’re coated on all sides with the soup. Arrange the coated chicken in a single, snug layer so it cooks uniformly.

Taste a bit of your mashed potatoes to be sure they’re well seasoned; adjust with a pinch of salt or pepper if needed before using them. The potatoes are your only seasoning beyond the soup, so they should be flavorful on their own.

Transfer the warm mashed potatoes to a piping bag fitted with a large star tip, or to a sturdy zip-top bag with one corner snipped off. Pipe the potatoes over the chicken in mounded swirls or rosettes, covering the entire surface of the casserole. Aim for some height and ridges in the potatoes—those edges will brown into the classic duchess-style peaks.

Place the casserole on the middle oven rack and bake, uncovered, for 30 to 40 minutes, or until the potatoes are deeply golden at the peaks, the sauce is gently bubbling around the edges, and the chicken pieces reach an internal temperature of 165°F (74°C) when checked with an instant-read thermometer.

Once baked, remove the casserole from the oven and let it rest for 5 to 10 minutes. This short rest allows the sauce to settle into a silky layer under the potato topping and makes it easier to serve neat portions.

To serve, slide a silver serving spoon down through the browned potato peaks and lift out a portion, making sure to scoop from the bottom so each serving includes tender chicken, creamy sauce, and plenty of golden duchess potatoes. Serve immediately while hot and the interior is still luxuriously soft.

You can stay true to the three-ingredient spirit while making small adjustments to suit your kitchen. If you prefer dark meat, use all boneless, skinless chicken thighs; they stay especially tender and forgiving if slightly overbaked. For a slightly different flavor, condensed cream of mushroom or cream of celery soup can stand in for the cream of chicken while keeping the same texture and ease. If you don’t have a piping bag, you can spoon the mashed potatoes over the top and use a fork to create ridges and peaks—drag the tines across the surface in swirls or crosshatch patterns to encourage browning. Make-ahead option: assemble the casserole up to the point of baking, cover, and refrigerate for up to 8 hours; when baking from cold, add 5 to 10 minutes to the oven time and check that the center is hot and the chicken reaches 165°F (74°C). Food safety tips: Always start with fully thawed chicken; baking from frozen can lead to uneven cooking and unsafe internal temperatures. Use a dedicated cutting board and knife for raw poultry, and wash your hands, tools, and surfaces with hot soapy water before handling other ingredients. Leftovers should be cooled quickly, covered, and refrigerated within 2 hours; reheat in a 350°F (175°C) oven until piping hot in the center or to at least 165°F (74°C) before serving again.