This creamy chicken and mushroom casserole is a real crowd-pleaser. I usually make a large batch and freeze half for a quick dinner another night. It works on the hob (stovetop) or in the oven, reheats well and makes plenty of sauce to pour over mashed potatoes and veg.
“Love the way the recipe is written, ie ingredients listed then in the method included again. Nutritional information, freezing advice all provided. The casserole was delicious!! Will be making again!!! Easy to follow instructions too!!! Thank you.”
– Sharyn McKay
Nicky’s Notes
Whenever the weather turns chilly I crave creamy sauces and mashed potato. This casserole ticks all the boxes: rich, comforting and simple to scale up.
Why I love making this as a big batch:
- Perfect for feeding a crowd — easy to make for 10+ people
- Can be prepared ahead of time
- Freezes well, so you can save portions for a fast future meal
Table of Contents
- Nicky’s Notes
- 📋 Ingredients for this Chicken & Mushroom Casserole
- 🧑🍳 Abbreviated Recipe
- Pro Tip
- 🍽️ What to serve it with
- 📺 Watch how to make it
- Creamy Chicken and Mushroom One-Pan Casserole Recipe
- 🍲 More fantastic Creamy Chicken recipes
📋 Ingredients for this Chicken & Mushroom Casserole
🧑🍳 Abbreviated Recipe
Full recipe with detailed steps in the recipe card below.
Coat the chicken in seasoned flour and brown it in hot oil in batches, then set aside. In the same pan, soften onions in butter with garlic, thyme and a little celery salt. Stir in flour and gradually whisk in chicken stock and milk until you have a smooth sauce, then add lemon juice. Return the chicken, add mushrooms, cover and simmer until cooked. Finish with cream and, if desired, thicken with a cornflour slurry.
Pro Tip
- Use a very large frying pan or a wide casserole pot — this recipe makes a generous amount.
If your household loves comfort food, expect a few minutes of quiet as everyone tucks in — always a good sign!
🍽️ What to serve it with
- Creamy mashed potatoes
- Crispy sautéed potatoes
- Garlic-parmesan green beans
- Oven-roasted broccoli
There’s plenty of sauce in this dish, so you’ll have enough to drizzle over chicken, potatoes and vegetables.
📺 Watch how to make it
Video demonstration available in the original recipe post.
Creamy Chicken and Mushroom One-Pan Casserole Recipe
15 mins
50 mins
1 hr 5 mins
Ingredients
Chicken:
- 5 chicken breasts (1kg / 2.25 lb), chopped into large chunks or strips
- 45 g (6 tbsp) plain (all-purpose) flour
- ½ tsp salt
- ½ tsp black pepper
Sauce:
- 2 tbsp oil
- 2 tbsp unsalted butter
- 3 small–medium onions, peeled and finely diced
- 5 cloves garlic, peeled and minced
- 1 tsp dried thyme
- ½ tsp celery salt (optional)
- 25 g (3 tbsp) plain (all-purpose) flour
- 1 litre (4 1/4 cups) chicken stock
- 300 ml (1 1/4 cups) milk (whole or semi-skimmed)
- 2 tbsp freshly squeezed lemon juice (about 1 lemon)
- 20 chestnut mushrooms, thickly sliced
- ½ tsp salt
- ½ tsp pepper
- 240 ml (1 cup) double (heavy) cream
- 2 tbsp cornflour mixed with 5 tbsp cold water to make a slurry (optional)
- small bunch parsley, chopped
Serve with:
- Mashed potatoes
- Sprouts
- Peas
- Sweetcorn
Instructions
- Place the chicken in a bowl with the 45 g flour, ½ tsp salt and ½ tsp black pepper. Toss until the chicken is evenly coated.
- Heat 2 tbsp oil in a large frying pan over high heat. In two batches, add the chicken and brown on all sides — it does not need to be cooked through. Remove with a slotted spoon and set aside.
- Reduce the heat to low–medium and add the butter. When melted, add the onions, garlic, thyme and optional celery salt. Cook for about 5 minutes until the onions soften. Sprinkle on the 25 g flour and stir for a minute; it may look slightly lumpy.
- Pour in a splash of the chicken stock and whisk to combine. Continue adding stock a little at a time, whisking as you go, until all stock is incorporated and you have a smooth sauce (the onions will remain in the sauce).
- Stir in the milk and continue to cook and stir until the sauce thickens. Add the lemon juice.
- Add the sliced mushrooms, the browned chicken and the extra ½ tsp salt and ½ tsp pepper. Cover and simmer gently on the hob for 20 minutes, until the chicken is cooked through.
- Alternatively, transfer everything to a casserole dish, cover with foil and bake at 175°C / 350°F (fan) for 30 minutes.
- Remove the lid, stir in the cream and heat through for 5 minutes (or return to the oven if using that method).
- If you prefer a thicker sauce, stir in the cornflour slurry a little at a time until you reach the desired consistency.
- Serve with mashed potatoes and your choice of vegetables, finishing with a scattering of chopped parsley.
Notes
Make Ahead
You can prepare this casserole ahead, cool it, cover and refrigerate for up to one day. Reheat covered in the oven at 175°C / 350°F for 20–25 minutes or warm on the hob over medium heat for 10–15 minutes until piping hot. Add a splash of cream or milk if it needs loosening.
Freezing
Cool the cooked casserole, cover and freeze. Defrost thoroughly in the refrigerator before reheating — warm in a covered oven at 175°C / 350°F for 20–25 minutes or on the hob for 10–15 minutes until heated through.
Scaling Down
You can halve the quantities if needed; cooking times remain the same.
Slow Cooker
I haven’t tested this recipe in a slow cooker yet. If you try it, let me know how it turns out.
Nutritional information is approximate and does not include the suggested sides (mashed potato, sprouts, peas and sweetcorn).
Nutrition
Carbohydrates: 13 g |
Protein: 25 g |
Fat: 18 g |
Saturated Fat: 8 g |
Cholesterol: 101 mg |
Sodium: 887 mg |
Fiber: 1 g |
Sugar: 5 g
Nutrition information is automatically calculated and should be used as an approximation.
This post was first published in September 2017 and updated in February 2023 with new images and a recipe video. It has received further updates for clarity and housekeeping since then.
🍲 More fantastic Creamy Chicken recipes
Chicken
Chicken a la King
Soups
Chicken and Rice Soup
Dinner
Creamy Chicken and Potato Bake
Chicken
Creamy Tuscan Chicken
One Pot
One Pot Rigatoni Alfredo with Chicken
Dinner
Chicken and Mushroom Pie
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