Rachel Roddy's Recipe for Zucchini, Potato and Bechamel | A kitchen in Rome

Being told to stir the white sauce in a figure eight was an important lesson. I have no idea of ​​my age. At what age do you let a child hold a pot of boiling milk and tell it to stir for 10 minutes? Seven? New? Eleven? However old my hand was, I remember it was guiding the wooden spoon. Carefully at first, in case the milk leaked out and burned my arm or a passing brother, but then it picked up speed. turn in a circle: skilful, like skating in milk or piloting a kite when the wind is good. Different again when the milk started to thicken and resist the curl. It was exciting, and even though I knew Mom had done something in the beginning, it was miraculous. It wasn't the first time I'd seen a one-pot transformation, but it was definitely the most satisfying and tangible. My smooth sauce was praised, cheese added, the sauce folded over cauliflower or pasta and the pan licked. I couldn't wait to do it again.

At some point I learned what mom had done in the beginning. Melt the butter, then add the flour so that it freezes into a dough that is intended to be a ball. Red ! To which you add milk, slowly, so that it becomes an even stickier paste. I was told to "whip the lumps". Next thing I knew, it was thin again. What a rollercoaster! “Incorporate a figure of eight. Be patient. It will thicken. But will he? It was like being tasked with setting up a magic trick: even if done perfectly, it could still go wrong.

Four decades and hundreds of pans more late, I have the exact same set of thoughts every time. Too thick. Too thin. Nothing good will come of it. Luckily, the figure eight through the milk is still there too, so between my worry and an endless loop is a good pot of white sauce, béchamel or besciamella. The last pan was for today's dish, a potato and zucchini gratin. The result of haste and scrolling past an image of a golden pastry and assuming it was bound by bechamel, when in fact it was yoghurt and egg. The photo comes from the Sardinian chef Andrea Locci, whom I trust (and who I usually read with great care), so I will do his version soon. Meanwhile, my mistake, which is like a cross between a potato gratin and a cauliflower and zucchini cheese, turns out to be a new family favorite.

Serve with a green salad and, if you like, a hot sauce shake. I can't wait to make it again.

Zucchini, potato and béchamel pastry

Prep 15 minCooking 1 hourServes 4

3 large potatoes (approx. 600g) 3 large courgettes (approx. 600g) 50g butter, plus extra for greasing and finishing 50g plain flour 600ml whole milk 60g grated Parmesan cheese Salt and black pepper Nutmeg 1 handful of fine breadcrumbs

Peel the potatoes, hull the courgettes. Using a mandolin, the cheese slicer on a box grater, or with a sharp knife and a steady hand, thinly slice both vegetables - don't worry if they're uneven or not sliced whole. Wipe all the cut slices with a kitchen towel.

Now prepare the béchamel. In a saucepan over medium heat, melt the butter, then add the flour and stir to obtain a thick roux. Gradually whisk the milk into the batter - it will thicken and then thin out. Continue cooking over medium heat, stirring firmly in a figure eight pattern, until thick enough to slowly fall off the back of the spoon. Add half the cheese, taste and season with salt, pepper and nutmeg.

Heat the oven to 200C (180C fan)/gas 6. Butter a baking dish. oven or pyrex, tilt in all the potatoes and zucchini, sprinkle with salt and mix. Pour over the béchamel and stir as best you can so that the vegetables are covered in the sauce. Level the top, sprinkle with remaining cheese and a handful of breadcrumbs, and sprinkle with butter.

Cover lightly with foil and bake for 40 minutes, removing the foil for the last 10 minutes to brown the top.