AsYotam Ottolenghi once said herebefore, a lasagne doesn’t have to contain ragu and bechamel. In the broadest sense, lasagne is just a layered pasta dish using various fillings and sauces and, as such, the world is your lasagne. This particular one came about because I was so extremely excited about British asparagus arriving early this year that I bought far too much of it, so had to come up with a starring role for it at the dinner table. I hithered and thithered about baking the asparagus, in case it lost its freshness, but I needn’t have: it’s still fresh-tasting and, like any good lasagne, comforting to boot.
You’ll need a food processor for the asparagus and a roughly 20cm x 30cm baking dish or oven tray. This is best served fresh and warm, but if you don’t get through it all in one go, it’s delicious if reheated in a hot, dry frying pan the next day.
Prep20 minCook1 hrServes6
80g unsalted butter4 tbsp plain flour(40g)1 litre whole milk160g pecorino(make sure it’s a vegetarian one), finely grated2 big pinches coarsely ground black pepperFine sea salt2 bunches asparagus(about 900g), woody ends snapped or cut off and discarded, the rest rinsed5 garlic cloves, peeled and sliced paper-thin2 leeks(350g), greens and whites finely sliced, rinsed and drainedFinely grated zest of 1 lemon25g fresh mint, leaves picked and chopped500g packet dried lasagne sheets(you won’t need them all)
First make the pecorino bechamel. Melt half the butter in a saucepan on a medium heat, then add the flour and cook, stirring constantly, for one to two minutes, to make a thick paste, or roux. Gradually whisk in the milk, beating regularly to prevent lumps, then, after about eight minutes, when the mixture thickens to a consistency of thick double cream, add half the grated pecorino, a couple of big pinches of black pepper and a half-teaspoon of salt. Mix well and take off the heat.
Roughly pulse the asparagus in a food processor until the spears have broken down into coarse, ½cm pieces with a rubble texture. In a wide frying or saute pan on a medium heat, melt the remaining 40g butter, then add the garlic and cook, stirring, for a minute or two, until softened. Stir in the sliced leeks, cook for four minutes, until wilted, then add the asparagus rubble and stir-fry for five to six minutes, until the asparagus has softened but still has some bite. Stir in the lemon zest, mint and three-quarters of a teaspoon of salt.
Heat the oven to 200C (180C fan)/390F/gas 6. Sprinkle half the asparagus mix in the base of a 20cm x 30cm oven tray or baking dish. Layer enough lasagne sheets side by side on top to cover, then ladle in half the pecorino bechamel and spread it out evenly. Repeat the layers one more time, then top the final layer of bechamel with the remaining 80ggrated pecorino. Bake for 30 minutes, until golden and bubbling, remove and leave to rest and settle for 15 minutes, then serve.