Preheat the oven to 180C/350F/Gas 4.
Heat the oil in a large frying pan. Add the mince and cook until brown all over, then remove from the pan with a slotted spoon and set aside.
Add the onions, peppers and mushrooms and fry over a medium heat until softened.
Return the mince to the pan. Add the tomato purÃ©e and bay leaves and cook for five minutes.
Add the tomatoes and dried herbs and heat to bring to the boil. Reduce the heat to simmer for at least 30 minutes. Season, to taste, with salt and freshly ground black pepper.
Grease a 25 x 20cm/10 x 8in baking dish and line the bottom with pasta.
Remove the bay leaves from the mince mixture and spoon about one third of the mixture onto the pasta.
Place blobs of cottage cheese (again totalling one-third of the cottage cheese) on top of the mince.
Repeat this layering process of lasagne sheets, mince and cottage cheese for more layers, finishing with a good sprinkling of cheddar all over the top.
Transfer to the oven and bake for about 45 minutes to 1 hour, until the top is golden-brown and bubbling and the pasta cooked through.
To serve, cut out squares of the lasagne and place onto plates. Serve with a green salad and garlic bread.