Spray a large non-stick frying pan with a little low-calorie cooking spray and place over a medium heat. Fry the beef for 8-10 minutes or until browned, then drain off any fat and transfer to a plate. Keep warm.

Add the onion, carrot, celery, mushrooms and 3 tsp water to the pan and cook for 10 minutes, adding a little more water if anything starts to stick. Return the beef to the pan and add the garlic, chopped tomatoes, passata, tomato purée, beef stock cube, Worcestershire sauce, oregano, half the basil and 300ml boiling water. Bring to a gentle boil and simmer for 10 minutes or until thickened. Season to taste.

Meanwhile, make the sauce. Put the squash, potatoes, vegetable stock cube and 450ml boiling water in a medium saucepan over a high heat. Bring to the boil, cover and simmer for 15 minutes or until tender. Remove from the heat and, without draining, add the remaining sauce ingredients. Whizz until smooth with a stick blender, add the remaining basil and season to taste.

Preheat your oven to 200°C/fan 180°C/gas 6 and spray a 30cm x 20cm ovenproof dish with a little low-calorie cooking spray.

Spoon one-third of the beef mixture into the bottom of the ovenproof dish and cover with lasagne sheets, snapping them to fill any gaps. Repeat these layers twice more, finishing with a layer of lasagne sheets that covers the beef completely. Pour over the sauce, pushing the sheets into the sauce a little, and bake for 35-40 minutes or until the lasagne is cooked through. Delicious served with salad.