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!
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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 (4.25 cups) chicken stock
- 300 ml (1.25 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
- **Optional** 2tbsp cornflour (cornstarch in USA) - mixed with 5 tbsp cold water – to make a slurry
- 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, ½ tsp salt, ½ 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 (4.25 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 (1.25 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, ½ tsp salt, ½ tsp pepper
- **Alternatively you can transfer to a casserole dish at this point. Cover with foil and place in the oven at 175C/350F 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.**Optional** 2tbsp cornflour (cornstarch in USA)
- Serve the casserole with vegetables (I like to serve mine with sprouts, peas and sweetcorn) and a sprinkling of parsley.Small bunch parsley
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
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.
Some of the links in this post may be affiliate links – which means if you buy the product I get a small commission (at no extra cost to you). If you do buy, then thank you! That’s what helps us to keep Kitchen Sanctuary running. The nutritional information provided is approximate and can vary depending on several factors. For more information please see our Terms & Conditions.
Sue says
Tried this in my slow cooker today. Followed the recipe exactly apart from using chicken thigh fillets, garlic granules instead of fresh cloves & homemade chicken stock.
Left out the milk & cooked on low for 6 hours.
Turned out absolutely delicious with a lovely thick sauce. I had a small jug of double cream on the table for those that wanted to mix it in but it didn't really need it.
Served with jacket potatoes & green beans.
Will definitely be making again, thank you 🙂
Smith says
My wife fell in love with me all over again
Audrey Harwood says
Love this recipe. Can I add white wine to make it a bit special. If so when & how.
Caroline Millers says
We both enjoyed this! Very flavoursome sauce. I used chopped chicken thighs and small whole portobello mushrooms served with rice. Will definitely cook again. Thanks
Polly Priest says
Hi Nicky and Chris I’ve just recently come across the Kitchen Sanctuary and your recipes are fantastic. I feel so inspired, I want to try them all! Last night I made this chicken and mushroom casserole and it is DIVINE! Off to make some Saag Aloo now 😀. Thank you for these great recipes xx
Graham Snow says
This was delicious,but my sauce was very runny.was this because I never stirred it slowly enough?
Diane says
Just wondering could I cover with puff pastry and bake ? Looks yummmy
Nicky Corbishley says
Absolutely! I bet that would be fab 🙂
George Hoad says
all100%proper peoples grub thank you and gord bless you