Lasagne of unprecedented extravagance

November 10, 2012

I've been revelling in our recent couple of obligation-free weekends. We've done a lot of exploratory eating, and on Saturday we scheduled my ideal combination of unhurried sunny-day cycling, eating out, browsing markets and op-shops, then lazing at home and spending a few hours in the kitchen trying something new.

We'd picked out a mushroom lasagne from Plenty for dinner. Lasagne is a bit of a project at the best of times, and Ottolenghi consistently leans towards the lengthy and the complicated. To wit: this lasagne involved four kinds of mushroom and five kinds of cheese. We committed, raiding the market delis for fresh lasagne sheets and fancy dairy, and the organic aisle for herbs and fungi. And after we spent money, we spent time; soaking and chopping mushrooms, whisking up two cheese sauces, grating yet more cheese, cursing dry lasagne sheets and carefully layering it all together, then not-quite-patiently letting it all melt and bake into the monstrosity you see pictured above.

It was a delicious monstrosity. I'm fond of mushrooms in cream sauce, and this has allowed me to eat them all week (and a whole lot of rocket besides). While the lasagne has been a pleasure, I can't help wondering if those five deli-sourced cheeses might have brought even more if we'd rationed them out and appreciated them individually. But then I'd've lost the pleasure of a weekend cooking project, I suppose.

Lasagne of unprecedented extravagance
(aka Mushroom Lasagne in Yotam Ottolenghi's Plenty,
recipe online here)

mushrooms
15g dried porcini mushrooms
400mL lukewarm water
60g butter
1 tablespoon thyme leaves
200g portobella mushrooms, 420g Swiss brown mushrooms, 240g button mushrooms
2 tablespoons chopped tarragon
4 tablespoons chopped parsley

lasagne
60g butter
3 shallots, finely chopped
60g plain flour
550mL milk
375g ricotta
1 egg
150g feta, crumbled
170g gruyere, grated
400g lasagne sheets
150g mozzarella, grated
50g parmesan, grated
salt and white pepper

Place the dried porcini mushrooms in a small-medium bowl and cover them with the lukewarm water, leaving them to soak for 5 minutes. I used this time to prepare my herbs and other mushrooms. When the porcinis are soaked, drain them and reserve the liquid. Finely chop them up.

Melt the butter in a very large frypan. Add the thyme and all the mushrooms, including the soaked porcinis. Stir the mushrooms occasionally as they cook. When they've softened and are just starting to leak a bit of water, take them off the heat (Ottolenghi estimates 4 minutes, but I reckon ours took at least 10). Stir in the tarragon and parsley, plus some salt and pepper. Transfer it all to a large bowl.

Use the frypan to make a bechamel sauce. Start by melting the butter and cooking the shallots in it for a few minutes. Add the flour, stirring it all together to form a paste and cooking for another couple of minutes. Gradually whisk in the milk, trying your best to smooth out any lumps. Strain the mushroom liquid and leave aside the last bit, which probably has grit in it. Whisk the mushroom liquid into the sauce too. Whisk in a little salt and pepper. Bring the sauce to a boil, then turn down the heat to low and simmer it until thick (Ottolenghi reckoned 10 minutes but I reckon mine took half that!). Take the sauce off the heat.

In a small bowl, stir together the ricotta and egg until well mixed, then fold in 3 tablespoons of the bechamel and all of the crumbled feta. Add the gruyere to the remaining bechamel in the frypan, stirring it through until relatively smooth.

If you're using dry lasagne sheets, pour some boiling water over them and allow them to soak for a couple of minutes. Drain them. 

Preheat an oven to 180 C. Find a large baking dish to assemble the lasagne, ours is about 25 x 35cm and it was bursting at the seams with this recipe.

Pour one-fifth of the bechamel into the baking dish and spread it out. Cover the sauce with a layer of lasagne sheets. Spread over one-quarter of the ricotta mixture (I had to dab it around, it wasn't going to spread as a thin layer), spoon over one-quarter of the mushrooms, then one-quarter of the mozzarella. Repeat the bechamel-pasta-ricotta-mushroom-mozzarella process three more times. Pour over the last of the bechamel and sprinkle over the parmesan.

Cover the lasagne loosely with foil (so that it doesn't touch the top) and bake for 40 minutes. Remove the foil and bake for a further 10-15 minutes, until the parmesan top is golden. Allow the lasagne to rest for 10 minutes before serving.