As with most lasagne recipes, this one does take a little time, but it will feed a large crowd (or your family twice!) and it’s a pleasure to know you have something ready to pop in the oven as soon as you get home from that long walk or exhausting shopping trip. The béchamel is made with butternut squash, so it comes out a lovely bright colour.
To make the tomato sauce
Heat some butter, or coconut or olive oil in a medium saucepan and gently sweat the onion until soft and translucent.
Add the garlic and fry for another minute or so, before adding the rest of the ingredients.
Simmer for 15–25 minutes or until thick and somewhat reduced. If the sauce is too chunky, use a stick blender to blitz for a few seconds.
To make the lasagne
For the butternut béchamel, cook the butternut squash in a little water until tender. Drain and mash. You should end up with 350g mashed butternut squash.
Mix the arrowroot or kuzu with enough of the cold milk to dissolve it and form a thin paste. In a blender or with a stick blender, blend the rest of the milk with the mashed butternut mash until smooth.
Transfer the mixture to a small saucepan with the bay leaf and arrowroot or kuzu paste and heat, stirring continuously, until the mixture is simmering and starts to thicken. Cook for 1–2 minutes, then remove from the heat, generously season with salt and pepper and set aside. If the sauce is still too thin, add a little more kuzu or arrowroot dissolved in milk.
For the spring greens, heat some butter, or coconut or olive oil in a medium saucepan and sweat the onion with a pinch of salt. Add the spring greens and sauté until wilted. Remove from the heat and leave to cool. Meanwhile, preheat the oven to 180 ̊C/350 ̊F/ Gas 4.
Put the ricotta, thyme leaves, eggs and sausage meat (or mushrooms) into a food processor and add the cold greens. Process until smooth.
To assemble, boil enough water to cover the base of a dish or shallow bowl that will fit 1 lasagna sheet. Steep the first lasagna sheet in the hot water for at least 10 seconds, or until it starts to soften. Remove and place in a medium ovenproof dish. Repeat until your first layer of sheets is complete. Break a sheet in half to fill any edges or corners if necessary.
Spread half the spring greens mixture over the lasagna, then half the Basic Tomato Sauce and half the butternut sauce. Repeat the process for the lasagna sheets with the second layer and repeat the layering of the sauces.
Top with the grated cheese, if using, and bake for 1 hour. Allow to stand for 10 minutes before serving, to give the lasagne a chance to firm up.
Good Better Green by Zita Steyn (Quadrille £16.99) Photography: Nassima Rothacker