Jews in Italy adapted traditional local dishes to conform to kosher rules, and in the process they created new and original recipes. This one is a great example. A kosher version of the traditional lasagne, using ricotta cheese and spinach rather than béchamel and meat. The ricotta is lighter than the béchamel, making it ideal for the summer months.

Preparation time: one hour. Serves four as main course or six as starter.

Ingredients
8-10 sheets dried egg lasagne pasta
1.2 kg passata or plum tomatoes in natural juice
½ teaspoon nutmeg
5-6 tablespoons extra virgin olive oil
1 finely chopped onion
500g fresh ricotta cheese
25g spinach
8-10 fresh basil leaves
Salt and black pepper
Freshly grated Parmesan

Method

• Preheat the oven to 180˚C / 350˚F / Gas Mark 4.
• First prepare the tomato sauce. Warm the olive oil in a frying pan over medium heat, add the onion and stir gently. Add a few tablespoons of warm water to the onion as this will help it soften while cooking.
• Once the onion turns golden, add the passata/plum tomatoes, and the salt and pepper. Cook over a low flame, covered, for about 30 minutes, stirring occasionally.  Turn off flame, add the basil and stir gently.
• While the tomato sauce is cooking, prepare the ricotta and spinach mixture. Wash the spinach well and, without draining it, put it in a deep saucepan, cover and let it steam. 
• Tip: You do not need to add any additional water when steaming the spinach, as it will release its own liquid while cooking. The spinach will also to retain more of its vitamins. 
• Cook for 5 minutes until the spinach is tender, then drain and squeeze the water out. Mix the spinach in a food processor together with some salt and pepper and nutmeg. Remove from the food processor and put in a bowl. 
• Gently add the ricotta and mix the ingredients thoroughly with a fork or whisk. Taste and add salt, pepper or nutmeg if needed.
• Fill a large saucepan with water and bring to the boil.
  Add 1 tablespoon of sea salt, a drizzle of oil and the sheets lasagne (3-4 at a time). Cook for 3 minutes or as directed on the package.
• With a slotted spoon, drain the lasagne sheets and lay them on a moist tea towel.
• Spread a thin layer of tomato sauce in a lasagne oven tray, of about 30x25cm (12x10in) in size. Add a single layer of lasagna pasta, trimming it to fit the tray as needed. Now add a few spoonfuls of tomato sauce, half the ricotta and spinach mixture and a little Parmesan.
• Start again and layer the next sheets of lasagna pasta on top, adding the same ingredients on top again. The third and last layer should be only of tomato sauce and Parmesan. 
• Put in the oven and bake for 20-25 minutes. Allow to stand for 10 minutes before serving.