Mary Berry Swiss Chicken, Spinach, And Mushroom Bake

The first time I made this, I forgot one key detail: squeezing the spinach dry. Thought it didn’t matter—oh, but it did. The whole bottom turned into a watery puddle, like a sad soup pretending to be dinner. Second time round? I wrung that spinach like my life depended on it—and suddenly, the whole thing held together beautifully.

This bake is now on heavy rotation in my kitchen. Tender chicken, garlicky spinach, a creamy mushroom sauce, and bubbling Gruyère over the top. It’s low-fuss, feels a bit fancy, and tastes like it took a lot more effort than it actually did.

Let me show you how to get it perfectly golden and rich—without the soggy bottom.

What Makes This Recipe Special

This one works so well because every layer plays its part. The spinach isn’t just filler—it’s garlicky, nutmeggy, and cooked down until almost creamy. The chicken gets a proper sear before baking, so it stays juicy. And the mushroom sauce? Honestly, I could eat it with a spoon.

The crème fraîche is the unsung hero here—it brings a slight tang and keeps the sauce rich without being heavy. And yes, the Gruyère is essential. I tried it once with Cheddar—it was fine, but Gruyère brings the proper melty stretch and nutty bite.

INGREDIENTS + WHY THEY MATTER

• Fresh spinach (750g) – Shrinks massively once wilted. You must squeeze out the liquid or it’ll flood the dish.
• Nutmeg – Sounds subtle, but it lifts the spinach from bland to “ooh, what’s that?”
• Mini chicken fillets – Quicker to cook and easier to portion. You can use full breasts, but slice them thinly.
• Olive oil + butter – Oil for searing, butter for the mushrooms. You need both for flavour.
• Button mushrooms – Keep their bite and don’t go slimy. I tried chestnut mushrooms—just as good.
• Garlic – Just one clove is enough. Too much and it overpowers.
• Crème fraîche – Makes the sauce creamy but not gloopy. Don’t swap for double cream unless you have to.
• Gruyère – Melts like a dream, with proper flavour. Swiss or Emmental can work, but they’re milder.

Ingredient Swaps That Hold Up

• No crème fraîche? Full-fat sour cream can work in a pinch, but add it off the heat or it might split.
• Cheese swaps? Swiss or mature Cheddar do okay, but Gruyère wins on melt and taste.
• Mushroom variety? Chestnut mushrooms add a deeper flavour. Avoid field mushrooms—they go soggy.
• Low-fat options? Don’t. I tried low-fat crème fraîche once—it split and went watery.

Mistakes I’ve Made (And How to Avoid Them)

What Went Wrong	Why It Happens	How to Fix It
Spinach made it watery	Didn’t drain or cook it enough	Squeeze it like a sponge, then dry fry
Chicken turned rubbery	Overcooked or didn’t sear first	Sear on high heat for flavour and texture
Sauce split in the oven	Used low-fat crème fraîche	Always use full-fat; add gradually
Mushrooms went soggy	Didn’t cook off the moisture	Fry until golden before adding crème fraîche

How to Make Mary Berry’s Swiss Chicken, Spinach, and Mushroom Bake

1. Prep the spinach – Wash, wilt in a large pan, then drain well and press out all moisture. Chop and cook again with nutmeg, salt, and pepper to dry further. Spread into a baking dish.
2. Cook the chicken – Preheat oven to 220°C (200°C fan). Season chicken. Sear in olive oil (in two batches) until golden, about 2 minutes per side. Place on top of the spinach.
3. Make the sauce – In the same pan, melt butter and fry mushrooms with garlic, salt, and pepper until golden and most moisture is gone. Stir in crème fraîche bit by bit to create a smooth sauce.
4. Assemble the dish – Pour the sauce over the chicken, using a fork to separate fillets slightly so sauce seeps through. Sprinkle Gruyère evenly on top.
5. Bake and rest – Bake for 30 minutes until golden and bubbling. Let sit for 5 minutes before serving so everything settles.

Tips From My Kitchen

• I always use a 2-litre ceramic dish—it bakes more evenly than metal.
• I start the mushrooms in a dry pan to get rid of moisture, then add butter for flavour.
• If you prep the spinach earlier, keep it in a tea towel—easiest way to wring it dry.
• A splash of white wine in the mushroom pan (before crème fraîche) adds lovely depth.

Storage and Serving

• Fridge: Keeps well for up to 3 days, tightly covered.
• Freezer: Freeze whole or in portions. Wrap tightly. Thaw overnight in fridge.
• Reheating: Oven at 180°C (160°C fan) for 15 minutes or until hot.
• What to serve with: Crusty bread, mashed potatoes, or a sharply dressed green salad.

FREQUENTLY ASKED QUESTIONS

Can I use frozen spinach?
Yes, but thaw it fully and squeeze out all the water. You’ll need about 250g frozen to match fresh once drained.

Can I use full chicken breasts?
You can—just slice them thin so they cook through. Fillets are quicker and more tender though.

What if I hate mushrooms?
You can skip them, but you’ll need something to bulk up the sauce—try caramelised onions instead.

Does this freeze well?
Yes. Freeze in portions or the whole dish. Reheat from thawed for best texture.

Can I prep this ahead?
Absolutely. Assemble it earlier in the day, cover, and refrigerate. Bake just before serving.

Try More Recipes:

• Mary Berry Harissa Chicken Recipe
• Mary Berry Chicken Legs With Smoky Bulgur Wheat
• Mary Berry Chicken Noodle Soup
• Mary Berry Chicken Marengo