Chicken, bacon and mushroom lasagne

This dish is based on a recipe from the side of a pack of Presto lasagne from many years ago. I even still have the original recipe, although Presto has long since gone out of business. Over the years I've adapted the recipe and it makes a regular appearance on our table throughout the year.

For the tomato layer:

1 leek, cleaned and sliced

1 tsp dried mixed herbs

275g mushrooms, cleaned and sliced

400g tin tomatoes

dash red wine

1 bay leaf

seasoning

For the chicken and bacon layer:

250g cooked chicken, chopped

175g cooked bacon, chopped

30g marg

30g cornflour

1 pint (450ml) chicken stock

300ml milk

320g lasagne sheets

For the topping:

75-100g grated cheese 

1. Gently fry the leek and mushroom with the dried herbs in a glug of olive oil until softened, about 5 - 10 minutes.
2. Add the tomatoes, red wine and bay leaf, season and simmer for 10 minutes.
3. In a separate pan, melt the margarine/butter, stir in the cornflour and cook gently for 2 or 3 minutes.
4. Stir in the stock and milk gradually, stirring constantly until a smooth sauce forms. (If I get lumps, I have been known to blast the sauce with a hand blender, but it's usually ok).
5. Take out about 1 pint of the sauce to use for the topping and set aside.
6. Stir in the cooked chicken and bacon into the remaining sauce, taste and season with salt and pepper if needed.
7. Stir half the grated cheese into the sauce you set aside for the topping.
8. Assemble the lasagne in a large baking dish, starting with a tomato layer, then lasagne, then chicken. Repeat these layers, then top the last layer of lasagne with the cheese sauce and sprinkle over the rest of the grated cheese. You will see in the picture that one corner is cheeseless, as we have a cheese hater in the family (he will tolerate the cheese in the sauce, but not the extra on top).
9. Bake at 190C for about 45 minutes, until the lasagne is cooked and the topping is golden brown.