How to Make Chicken & Mushroom Gratin

I’ve been wanting to make a gratin since reading sweetness & lightning… Gratin is pretty much all about the cheesy topping and, after a little experimenting, this is what I came up with. It looks quite fancy, but once you break it down it’s really quite simple!

You will need:

  • a sharp knife
  • a chopping board
  • two pans
  • an oven-proof dish

and the ingredients (for 4 people):

  • 4 chicken (or Quorn) fillets
  • 8 medium, or 16 small, mushrooms
  • 300-350ml milk
  • roughly 1tsp cornflour
  • 1/2 chicken stock cube
  • 1 onion
  • hard cheese such as cheddar
  • crackers or oatcakes, the kind you like with cheese

 

Start by putting your chicken on to fry. (We’re using the same technique I wrote about earlier this month, so if there’s anything you’re not sure about, see my earlier post here.)

Hand drawing of a frying pan containing four pink chicken fillets

Chop your mushrooms into cubes, or slices if you prefer (you can find instructions for both here). Then, add them to the frying pan.

Hand drawing of a frying pan containing chicken fillets and chopped mushrooms

Let the chicken and mushrooms cook while you work on your sauce. (This is a white sauce, so if there’s anything unclear, check out my post on white sauces here.) You can also turn on the oven to Gas Mark 6, 200°C (180°C fan), so it has time to preheat.

Place your saucepan on a gentle heat, and dice your onion. (You can find more detailed instructions here: onions). Add a little oil (less than a teaspoon is fine), followed by your diced onion.

Hand drawing of a saucepan with a thin layer of onion on the bottom

Give your onions a few minutes to gently fry, and soak up the oil, then add the milk. (If you want to save on washing up, you can use your serving dish to measure – you want about half as much milk as you’re going to have filling.)

Hand drawing of a saucepan filled with white sauce

Crumble half a stock cube into the milk, and add the cornflour to thicken the sauce. (Remember to mix the cornflour into a little cold liquid first to avoid lumps!) Let it gently simmer (you should see small bubbles, but no large ones) for 5-10 minutes.

During this time, crush your oatcakes or crackers. My favourite way to do this is to put them in a plastic bag, squeeze out the air, and smash them with a rolling pin. Or you could use a food processor. Grate your cheese, then mix it with the crushed biscuits.

 

Taste the sauce (this is why I like to cook it separately from the chicken). If it tastes like it’s lacking something, you could try adding a little salt, pepper, or grated cheese.

Make sure the chicken is cooked and chopped into chunks. Mix together the chicken, mushrooms, and sauce, then add to the oven-proof dish. (I like to use individual dishes for serving – to make them easy to take in and out of the oven, pop them all on a baking tray.) Try and flatten the chicken mixture roughly level.

Hand drawing of a small oven-proof dish filled with chicken and sauce

Top with the mixture of cheese and crumbs. To crisp up the top, place them in the preheated oven for 5-10 minutes. If you’ve forgotten to preheat the oven, you can do this under a hot grill instead.

26.6 Topping

And it’s done! This is quite a rich dish, so a simple side of steamed or boiled vegetables or even a salad is perfect. And if you’re looking for more variations, there are plenty! You could add blue cheese to the sauce, swap the mushrooms for bacon, or simply add a little parsley to the sauce.

If you make chicken and mushroom gratin with this recipe, I’d love to see a picture of your finished dish!

Also, what did you think of the different style of pictures for this recipe?

How to Make a White Sauce

A white sauce is a sauce made using milk. It has a mild, creamy flavour that complements a range of ingredients, including mushrooms, chicken and fish.

The first thing to decide when making a white sauce is what kind of milk you want to use. If you’re using dairy, using skimmed milk will give you a very thin sauce, so I would recommend at least semi-skimmed. If you’re using a non-dairy milk, you need one with more fat and protein than sugar. This means that soy and nut milks will work, but things like coconut milk won’t. And, if possible, use an unsweetened milk.

The next thing to decide is how to flavour your sauce. I like to start a white sauce by gently frying some diced onion (cutting tutorial here) or crushed garlic in a little oil before I add the milk. You can also add a stock cube directly to the milk as you heat it – try and match the flavour of the stock to the ingredients you plan to put in the sauce. You could also add a little grated or cream cheese for richness, nutmeg for a little spice,  or some dried parsley.

Finally, you’ll need to thicken your sauce. There are two main techniques you can use here.

The classic technique to thicken a sauce is called a roux. A roux starts by frying a spoonful of wheat flour in a little butter or oil. You have to be careful at this stage that the flour is cooked, or the resulting sauce will taste floury. You also have to be careful to avoid lumps – one way to do this is to add the flour to onions, rather than directly into the pan. After a few minutes of frying, you can add your milk. To avoid lumps (again), you need to add it very slowly at first, and keep stirring!

It can be quite easy to get a roux wrong, so the thickening method I prefer is cornflour. Simply mix together one spoonful of cornflour with one spoonful of cold water or milk. Then, add the cornflour mix to your sauce. The great thing about this method is that it can be done last-minute, there’s no floury aftertaste, it’s a lot easier to avoid lumps, and it’s even gluten-free!

Whichever method you use, a white sauce is really versatile. You can use it with all kinds of fish, in pasta dishes like lasagna, or in a chicken and mushroom pie…

One final thing though – if you have leftover white sauce you may find that it sets when chilled, especially if you used cornflour as a thickening agent. This is perfectly normal and doesn’t mean the sauce has gone off; it will go right back to liquid when you heat it up again.