Wash the greens well and trim off any large stems, then parboil them for a few minute, just until they have wilted. Drain, squeeze dry and roughly chop them.

Sauté the onion in a skillet with a generous glug of olive oil until it is soft and translucent. Add the chopped greens and let them wilt, mixing all the time so they become impregnated with the flavor of the soffritto. Strip the leaves off the sprig of marjoram and add them to the greens, along with the nutmeg, clove, salt and pepper. Let the mixture simmer gently for a minute or two so the flavors meld. Turn off the heat and set aside to cool completely.

Mix the ricotta and Greek yogurt in a bowl, together with an egg, a healthy pinch of grated Parmesan, salt and pepper. (Some grated nutmeg or clove here, too, wouldn't be amiss.) Set aside.

Lay one sheet of the puff pastry over a well-greased 9 inch pie plate. (The pastry should hang over the sides of the plate; you may need to roll out a store-bought sheet a bit, as I did.) Lay the greens over the bottom. Top with half of the remaining grated Parmesan cheese.

Then lay on top the ricotta and yogurt mixture. Make 3 or 4 slight depressions in the filling with a wooden spoon, then break an egg into each well.

Season with salt and pepper, sprinkle with the rest of the grated Parmesan cheese, then finally drizzle everything with some olive oil.

Lay over the second sheet of puff pastry. Trim around the edges of the pie plate, leaving an overhang of about 2cm or 1/2 inch. Now roll up the extra pastry onto the pie plate, pressing the two sheets together as you go, to form a kind of cord.If you like, brush the puff pastry with beaten egg yolk for extra sheen.

Bake the pie in a pre-heated oven at 180C/350F for about an hour, or until the top is golden brown.

Let the torta pasqualina cool completely before serving.