This oven baked 3-ingredient sour cream onion chicken is exactly what my dad requested for his birthday dinner instead of going out to a restaurant. It’s simple, cozy, and tastes like something you’d get at a family-style place, but without any fuss. The chicken bakes up juicy under a blanket of tangy sour cream and sweet, caramelized onions, all in one casserole dish. It’s the kind of no-stress meal you can slide into the oven while you set the table and maybe bake a little birthday cake, too.
This chicken is wonderful served over buttery mashed potatoes, egg noodles, or simple white rice so all that tangy oniony sauce has something to soak into. Add a green side like steamed green beans, roasted broccoli, or a simple tossed salad with a bright vinaigrette to balance the richness. Warm dinner rolls or crusty bread are great for sopping up the extra sauce, and if it’s a special occasion like a birthday, follow it up with an easy dessert such as brownies or a boxed cake with homemade frosting.
Oven Baked 3-Ingredient Sour Cream Onion Chicken
Servings: 4

Ingredients
4 boneless, skinless chicken breasts (about 2 pounds total)
2 cups sour cream
2 large yellow onions, thinly sliced
1 teaspoon kosher salt (or to taste, optional)
1/2 teaspoon black pepper (optional)
1 tablespoon olive oil or butter for greasing the dish (optional)
Directions
Preheat your oven to 375°F (190°C). Lightly grease a ceramic casserole dish with olive oil or butter so the chicken doesn’t stick and the onions can caramelize nicely.
Pat the chicken breasts dry with paper towels. If they are very thick, you can gently pound them to an even thickness so they cook more evenly, but this is optional.
Season the chicken lightly with salt and pepper if using. Remember the sour cream and onions will add flavor, so you don’t need much.
Lay the chicken breasts in a single layer in the prepared casserole dish, leaving just a little space between each piece so the heat can circulate.
In a medium bowl, stir the sour cream until smooth. You don’t need to add anything to it; it will thin slightly as it bakes and mix with the onion juices to make a sauce.
Spread the sour cream evenly over the chicken breasts, covering the tops completely. It’s fine if some of it drips down the sides into the dish.
Scatter the thinly sliced onions all over the top of the sour cream-covered chicken, making sure they are spread out rather than clumped. Some will fall around the chicken into the dish, which helps them soften and caramelize in the juices.
Cover the casserole dish loosely with foil, tenting it so it doesn’t press down into the sour cream. Bake covered for 20 minutes to help the chicken cook through gently and keep it juicy.
After 20 minutes, remove the foil and continue baking, uncovered, for another 20 to 30 minutes, or until the chicken is cooked through (the thickest part should reach 165°F/74°C). During this time the sour cream will bubble and the onions will soften and start to caramelize around the edges.
If you’d like the top a little more golden, you can switch the oven to broil for 2 to 3 minutes at the end, watching closely so the sour cream and onions brown but do not burn.
Remove the casserole dish from the oven and let the chicken rest for about 5 minutes. This helps the juices settle and the sauce thicken slightly.
To serve, spoon the caramelized onions and tangy sour cream sauce over each chicken breast. Serve straight from the casserole dish at the table for a cozy, family-style birthday (or any night) dinner.
Variations & Tips
For picky eaters, you can scrape most of the onions to one side of the dish before serving and give them just the saucy chicken, or even bake one chicken breast in a small separate dish with only sour cream on top. If your family likes a little extra flavor but you still want to keep it simple, stir a packet of dry onion soup mix or a teaspoon of garlic powder into the sour cream before spreading it over the chicken. For a slightly lighter version, use light sour cream and smaller chicken cutlets; just start checking for doneness a bit earlier. If you prefer dark meat, substitute bone-in, skinless chicken thighs and add 10 to 15 minutes to the baking time, or until they reach 175°F and are very tender. To make it feel more like a restaurant dish for a birthday dinner, sprinkle a little fresh chopped parsley or chives over the top right before serving and bring the whole casserole to the table on a trivet. Leftovers reheat well; slice the chicken and warm it gently in the sauce, then serve over toast or rice for an easy next-day lunch.