Heat a generous drizzle of olive oil in a deep pan and add the chopped onion. Fry over a medium low heat until soft. Add the crushed garlic and fry for a further minute.
Add the passata and a good dash of mixed herbs and oregano and let simmer for 5 minutes.
Add the chicken, stock and tomato puree, and stir well; simmer for a further 5 minutes.
While the chicken and tomato sauce are simmering, melt the butter in a pot over medium heat and add the flour. Using a whisk blend together, then add the milk a little at a time over a medium high heat until it thickens. Add the Cheddar cheese and cook for a few minutes more, stirring regularly to avoid burning.
Take the fresh lasagne sheets and put a couple of tablespoons of the chicken mixture on them and roll up, placing them in an ovenproof dish with the seam facing down. Pour any leftover chicken mixture over the top.
Slowly pour the cheese sauce over the top, ensuring that all the pasta is covered. Sprinkle with the grated Parmesan.
Bake in the oven at 180 C / Gas 4 for about 30 minutes, or till hot and bubbly and slightly browned on top. Serve with garlic bread.
You can easily use leftover chicken for this recipe, like chopped leftover chicken from a Sunday roast. If using leftover chicken, use anywhere from 450g to 675g chopped cooked chicken.