This creamy chicken casserole is a real crowd pleaser. I make it as a big batch then freeze half for a quick dinner another night.
You can cook it on the hob (stovetop) or in the oven. It reheats beautifully, and there’s plenty of sauce to soak into your mashed potato and veggies!
I don’t know about you, but I desperately crave creamy sauces and mashed potato whenever the weather is even marginally cold.
This is one of my favourite big batch meals to make because:
- It’s great for feeding a crowd (easy to make for 10+ people)
- You can make it ahead
- It’s suitable for freezing….
- …..which also means you can eat some for dinner and freeze some for a super quick dinner next time
📋 What do we need?
📺 Watch how to make it
Full recipe with detailed steps in the recipe card at the end of this post.
👩🍳PRO TIP Make sure you’ve got a very large frying pan or casserole pan as this recipe is pretty big!
If your family are anything like mine when it comes to comfort food like this, you should hear lots of ‘Mmmms’ and chomping noises for the first 5 minutes, before the chatting resumes. Always the sign of a good meal!
🍽️ What to serve it with
I love that there’s plenty of sauce with this dish, so you’ve got enough to drizzle over your chicken, potatoes and vegetables ❤️
🍲 More fantastic Creamy Chicken recipes
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Creamy Chicken and Mushroom One Pan Casserole
Ingredients
Chicken:
- 5 chicken breasts (1kg/2.25 lb) chopped into big 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-to-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 milk or half-fat
- 2 tbsp freshly squeezed lemon juice juice of approx. 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, (cornstarch in USA) **Optional**
- small bunch parsley chopped
Serve with:
- mashed potatoes
- sprouts
- peas
- sweetcorn
Instructions
- Place the chicken in a bowl with the flour, salt, and pepper. Toss to cover the chicken in the flour and seasoning.5 chicken breasts, 45 g (6 tbsp) plain (all-purpose) flour, 1/2 tsp salt, 1/2 tsp black pepper
- Heat the oil over a high heat in a large frying pan (skillet) and working in 2 batches, add the chicken. Brown all over (it doesn't need to be cooked through at this point). Remove from the pan with a slotted spoon and put to one side.2 tbsp oil
- Place the butter in the same frying pan and melt over a low-medium heat. Add the onions, garlic, thyme, and celery salt and cook for 5 minutes until the onion softens. Sprinkle on the flour and stir for a minute (it will be lumpy).2 tbsp unsalted butter, 3 small-to-medium onions, 5 cloves garlic, 1 tsp dried thyme, ½ tsp celery salt, 25 g (3 tbsp) plain (all-purpose) flour
- Pour in a splash of the stock and stir, using a whisk until combined. Continue to add in stock, a little at a time, whilst stirring, until all the stock is added and you have a smooth sauce with no lumps (the onions will still be in there though – so it will look a little lumpy because of that).1 litre (4 1/4 cups) chicken stock
- Add the milk and continue to stir over the heat until the sauce thickens, then add in the lemon juice.300 ml (1 1/4 cups) milk, 2 tbsp freshly squeezed lemon juice
- Add the mushrooms, the cooked chicken and the salt and pepper. Place a lid on the pan and simmer gently on the hob for 20 minutes.20 chestnut mushrooms, 1/2 tsp salt, 1/2 tsp pepper
- **Alternatively you can transfer to a casserole dish at this point. Cover with foil and place in the oven at 175C/350F (fan) for 30 minutes**
- Remove the lid and stir in the cream, then heat through for a further 5 minutes (place back in the oven if oven cooking).240 ml (1 cup) double (heavy) cream
- If you'd like the sauce to be any thicker, then at this point you can stir in the cornflour slurry. Add a little splash at a time, whilst stirring, until you get the thickness you want.2 tbsp cornflour
- Serve the casserole with vegetables (I like to serve mine with mashed potatoes, sprouts, peas and sweetcorn) and a sprinkling of parsley.small bunch parsley, mashed potatoes, sprouts, peas, sweetcorn
Video
Notes
Heat through thoroughly in the oven (covered) at 175C/350F for approx 20-25 minutes. Or heat through on the hob for 10-15 minutes on a medium heat until the chicken is hot all the way through.
Add a splash of cream or milk if needed to loosen it up. Freezing: Make the casserole, then cool, cover and freeze. Defrost thoroughly in the refrigerator and heat through thoroughly in the oven (covered) at 175C/350F for approx 20-25 minutes. Or heat through on the hob for 10-15 minutes on a medium heat until the chicken is hot all the way through. Reducing the quantities: You can halve the quantities if necessary – no change to the cooking times. Can I make it in the slow cooker? I haven’t tried this one in the slow cooker yet. If you try it, please let me know how it went. I’ll update the notes when I test it using the slow cooker. Nutritional Information is approx. per serving WITHOUT Serving suggestion of Mash Potato, Sprouts, Peas and Sweetcorn.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
This post was first published in September 2017, then updated Feb 2019 and again in February 2023 with new images, recipe video and a bit of housekeeping.
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Absolutely delicious, chicken was so tender and the flavours were amazing.
Our new family fav- very flavoursome! I didn’t have the Mash, sprouts and corn – but served with rice and steamed Broccoli …so yum !!!
Cooked this tonight. And absolute hit! Love your recipes. Keep it up! Thank you
This casserole is seriously the bomb! There’s easily 8 adult serves here, I used 10 chicken thighs instead of 5 breast fillets.
The flavour is incredible, my husband has asked it to become a monthly regular. To have 2 dinners from it, and 4 frozen serves, it’s the best!
Made this for dinner along with the Mash potato, so good! Hubby and miss 2 yr old enjoyed it too:)
I made this today after googling a creamy mushroom casserole recipe, and I love it! This is exactly how I wanted my casserole to turn out. Will definitely be adding this to my recipe list.
I cooked up some rice and ended up with 10 meals I put in the freezer
Loved it. Really simple too.
Absolutely lovely and very tasty.
I served it with plain white rice.
It says that it serves 10, maybe six !
Made this for dinner last night, I served it with brown rice and put some spinach in with the chicken and mushroom. Delicious, definitely making this one again.
Just made the Chicken and Mushroom Casserole for 4. (There are three of us!!). Great meal! Clean plates all round!! Delicious!