Easy Creamy Chicken & Mushroom One-Pan Casserole Recipe

Introduction

Oh, friends, do I have a treat for you today! This Creamy Chicken and Mushroom One-Pan Casserole brings back all those cozy, comforting memories of family dinners and nights spent gathered around the table. It’s the kind of meal that just wraps you in a warm hug, and the best part? You can make it with minimal fuss and maximum flavor. Seriously, it’s so simple, you’ll wonder why you haven’t made it a weekly staple already!

Why You’ll Love This Recipe

• Fast: You can have this on the table in under an hour, perfect for those busy weeknights.
• Easy: With just one pan, cleanup is a breeze. Less scrubbing, more enjoying!
• Giftable: Make a batch and share it with a neighbor or a friend who needs a little comfort food.
• Crowd-pleasing: From picky eaters to seasoned foodies, everyone raves about this creamy, savory delight.

Ingredients

Gather your ingredients, and let’s get this deliciousness started!

• Chicken: 5 chicken breasts (about 1kg/2.25 lb), chopped into large chunks or strips. I like to use breasts because they’re lean and cook quickly, but feel free to use thighs if that’s what you have!
• For Coating the Chicken:
• 45 g (6 tbsp) all-purpose flour. This little bit of flour helps give the chicken a lovely golden crust.
• ½ tsp salt. Essential for bringing out all the flavors.
• ½ tsp black pepper. A classic pairing with chicken.
• For the Creamy Sauce:
• 2 tbsp oil. Your favorite cooking oil will do.
• 2 tbsp unsalted butter. For that extra richness and flavor.
• 3 small-to-medium onions, peeled and finely diced. Onions are the backbone of so many great sauces!
• 5 cloves garlic, peeled and minced. Because who can resist the aroma of garlic?
• 1 tsp dried thyme. A lovely herb that complements both chicken and mushrooms beautifully.
• ½ tsp celery salt (optional). If you have it, it adds a subtle savory depth.
• 25 g (3 tbsp) all-purpose flour. This will help thicken our glorious sauce.
• 1 litre (4 ¼ cups) chicken stock. Use a good quality one for the best flavor.
• 300 ml (1 ¼ cups) milk (whole or half-fat). Whole milk makes it extra creamy, but half-fat works wonderfully too.
• 2 tbsp freshly squeezed lemon juice (juice of approx. 1 lemon). A little brightness to cut through the richness!
• 20 chestnut mushrooms, thickly sliced. These little guys soak up all that creamy goodness.
• ½ tsp salt. To season the sauce.
• ½ tsp pepper. More flavor!
• 240 ml (1 cup) heavy cream. This is what makes it truly decadent and dreamy.
• 2 tbsp cornflour mixed with 5 tbsp cold water (cornstarch slurry). Our secret weapon for getting that perfect, luscious sauce consistency.
• Optional Garnish:
• Small bunch parsley, chopped. A pop of fresh green makes it look as good as it tastes!

How to Make It

Alright, let’s get cooking! It’s easier than you think.

1. First things first, let’s get our chicken ready. In a medium bowl, toss the chicken pieces with the 45g of flour, salt, and pepper. Make sure each piece is nicely coated.
2. Now, grab a large oven-safe skillet or a casserole dish. Heat the oil and butter over medium-high heat. Once shimmering, carefully add the floured chicken. Brown it on all sides until it’s got a lovely golden hue. Don’t overcrowd the pan; you might need to do this in batches. Once browned, scoop the chicken out and set it aside on a plate.
3. Into that same skillet, toss in your diced onions. Cook them, stirring occasionally, until they’ve softened up, which should take about 5-7 minutes.
4. Now, add the minced garlic and dried thyme. Stir it all around and cook for about another minute until you can really smell that wonderful fragrance.
5. Time to make our sauce base! Sprinkle the remaining 25g of flour over the onions and garlic. Stir it in really well and cook for 1-2 minutes. This creates a “roux,” which is the magical start to our creamy sauce.
6. Slowly, and I mean slowly, whisk in the chicken stock and milk, a little at a time. Keep whisking to make sure there are no lumps. Once it’s all in, bring the mixture to a simmer, stirring constantly.
7. Stir in the fresh lemon juice, your thickly sliced mushrooms, and season with the ½ tsp salt and ½ tsp pepper.
8. Nestle those beautifully browned chicken pieces back into the skillet.
9. Pour in the heavy cream and give everything a gentle stir to combine.
10. Bring the casserole back to a gentle simmer. Now, it’s time for our cornflour slurry. Stir in the mixture of cornflour and cold water. Keep stirring as the sauce thickens up to your desired consistency – usually about 5-10 minutes.
11. If you’re serving this right away, just continue to simmer gently until the chicken is cooked through and the sauce is wonderfully thick and creamy.
12. If you’re planning ahead, or if your skillet isn’t oven-safe, transfer everything to a separate oven-safe dish. Cover it tightly and pop it in the fridge until you’re ready to bake. When you’re ready, bake in a preheated oven at 180°C (350°F) for 20-25 minutes, or until the chicken is cooked through and the sauce is bubbling merrily.
13. For a final flourish, garnish with that fresh chopped parsley if you like!
14. Serve this gorgeous casserole hot, perhaps with some fluffy mashed potatoes, steamed broccoli, or even some sweetcorn. It’s pure comfort on a plate!

Substitutions & Additions

This recipe is wonderfully adaptable! Don’t be afraid to make it your own.

• Chicken: While chicken breasts are classic, you could use boneless, skinless chicken thighs for a richer flavor.
• Mushrooms: If chestnut mushrooms aren’t your favorite, try cremini, shiitake, or even a mix!
• Vegetables: Feel free to toss in some frozen peas, corn, or diced carrots along with the mushrooms for extra color and nutrients.
• Herbs: Fresh thyme or rosemary would be lovely additions.
• Cheesy Goodness: Stir in some grated Parmesan cheese or shredded cheddar cheese at the end for an extra layer of flavor.

Tips for Success

A few little pointers to ensure your casserole turns out perfectly every time!

• Don’t skip browning the chicken: This step is crucial for developing flavor and texture.
• A smooth sauce is key: Whisk the flour into the onions and garlic well before adding the liquids, and add your stock and milk gradually while whisking to prevent lumps.
• Thickening the sauce: The cornflour slurry is your best friend for achieving a luscious, non-watery sauce. Make sure it’s fully incorporated and simmered until thickened.
• Prep ahead: You can brown the chicken and prepare the sauce base (up to step 10, before adding the cream and slurry) a day in advance. Store them separately in the fridge, then combine and finish cooking when you’re ready to serve.

How to Store It

Leftovers? Lucky you! This casserole keeps beautifully.

Once cooled, store any leftover casserole in an airtight container in the refrigerator for up to 3-4 days. Reheat gently on the stovetop or in the microwave until heated through.

FAQs

Got questions? I’ve got answers!

Can I make this ahead of time?

Yes! You can prepare the casserole up to the point of simmering (step 10), let it cool, and then refrigerate. When ready to serve, reheat gently on the stovetop or bake in the oven as directed.

Can I freeze this casserole?

While it can be frozen, the texture of the sauce might change slightly upon thawing. If you do freeze it, thaw it completely in the refrigerator before reheating.

What can I serve this with?

This casserole is fantastic with mashed potatoes, rice, crusty bread for dipping, or a side of steamed green beans or a fresh salad.

My sauce isn’t thick enough, what should I do?

If your sauce is still too thin after simmering, you can make another small cornflour slurry (1 tbsp cornflour mixed with 2 tbsp cold water) and stir it in, simmering until thickened.

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