One of the first recipes we made in Ballymaloe, actually I think the very first thing we cooked, was mushroom a la crème. Chopping mushrooms was a technique that we learnt early on, and as I love mushrooms very much, a technique that will stay with me I hope.
First the onions have to be finely diced, another technique. One of the things I said I needed to learn was how to correctly slice an onion. And I haven’t looked back!
Then a knob of butter is melted in a shallow saucepan until foaming. To this the diced onions are added, and a good seasoning of salt and pepper at this stage starts the symphony of flavours that will make up the final dish. I turn the heat right down under the pot, and cover the onions with a butter wrapper and a tight fitting lid, leaving them to cook very gently until opaque, not coloured.
Meantime, I chop the mushrooms and cook them over a high heat in a frying pan with a little butter. I also season each batch of these, with salt, pepper and a small squeeze of lemon juice. They are cooked in batches to prevent the pan getting too cool, which ends up steaming the mushrooms, not frying them. They must be cooked until golden in colour, this adds texture to the sauce, and removes all chance of floppy, slimy, tasteless mushrooms.
Once all the mushrooms are cooked they are added to the onions, then a generous pour of cream over the whole lot finishes it off. This is brought to bubbling, and can be served straight away, or kept and reheated later. As an aside, in the Ballymaloe recipe it says that you can add a little roux to the sauce once the cream is added to thicken it. I find that if you let the sauce bubble away very very slowly, it comes to a very agreeable consistency all by itself.
It seems alot of work for such a simple sounding sauce, but it pays off. I have two favourite ways of serving it; with lobster and linguine (Thanks Jared), and simply with roasted chicken thighs and some buttery orzo.