1

Mist a nonstick pan with cooking spray. Add the leeks and 2 tablespoons water and cook, uncovered, for 10 minutes. Transfer to a bowl. Mist the pan again and fry the chicken, in batches, for 10 minutes until cooked. Add to the bowl of leeks, stir in the tarragon and season.

2

Mist the pan again, fry the mushrooms for 5 minutes, then add the garlic and spinach and cook, covered, for 3 minutes. Increase the heat and cook, uncovered, until the liquid evaporates. Season and set aside.

3

To make the cheese sauce, mix 3 tablespoons of the milk with the cornflour in a jug to form a paste, then stir in the remaining milk. Pour the mixture into a pan, add the soft cheese and cook over a low heat, stirring, until smooth. Bring to a boil and cook for 2 minutes, or until thickened. Season and stir through the lemon zest.

4

To assemble, divide one-third of the cheese sauce between 2 medium baking dishes (around 25cm x 17cm). Top each with one-quarter of the chicken mixture followed by 3 lasagne sheets. Divide the spinach mixture between the 2 dishes, then repeat with the cheese sauce, chicken mixture and lasagne sheets. Finish with a layer of cheese sauce, then scatter over the Parmesan.

5

Preheat the oven to 200°C, fan 180°C, gas mark 6 and bake one of the lasagnes for 40-45 minutes until golden and bubbling. Serve with a green salad.