Spring Comfort: Just 3 ingredients. The recipe my mother-in-law refused to share until last year.

This recipe is meant to be as simple and comforting as the woman who guarded it, but there are a few gentle ways to make it your own without losing its spirit. For a slightly tangier sauce, you can use full-fat plain Greek yogurt in place of up to half of the sour cream, keeping the rest the same. If you prefer white meat, boneless, skinless chicken breasts work fine—just cut them into even pieces so they cook at the same rate, and check for doneness at the 40-minute mark so they don’t dry out.

For a bit more color and a spring feel, you can scatter a handful of frozen peas over the chicken before adding the sauce, understanding that this technically adds another ingredient beyond the classic three. A sprinkle of black pepper or a pinch of dried thyme on top before baking also adds a little depth without changing the character of the dish. For food safety, always start with fresh or properly thawed chicken; never bake this casserole from frozen.

Keep raw chicken and its juices away from ready-to-eat foods, wash your hands and cutting board thoroughly after handling it, and use a clean thermometer to ensure the chicken reaches 165°F (74°C) in the thickest pieces. Leftovers should be cooled and refrigerated within 2 hours, stored in a covered container, and eaten within 3 to 4 days. Reheat gently in the oven or microwave until hot and bubbling, adding a spoonful of sour cream if the sauce seems too thick after chilling.