Preheat the oven to 190°C. In a bowl add the beef mince, egg, garlic granules, onion powder, mixed herbs and a good pinch of salt and pepper. Mix together with your hands until well combined, then roll into 12 equally-sized balls.
Spray a frying pan with low-calorie cooking spray and set on a medium to low heat. Add the meatballs and cook until golden brown, turning as you cook to get an even colour. Remove from the pan and set aside.
Spray the same frying pan with low-calorie cooking spray and place back over a low to medium heat. Add the onions and peppers, and cook for 5 minutes until they begin to soften.
Add the carrot, courgette and garlic and continue to cook for a further 5 minutes.
Crumble in the stock cube then add the chopped tomatoes, balsamic vinegar, Henderson's relish, tomato puree, oregano and mix well. Simmer for 5 minutes. At this stage, we blitzed half the vegetables in the pan with a stick blender to create more of a tomato sauce texture; you can leave it as a chunky vegetable mixture, if you prefer. Once you have blitzed half the vegetables, stir through the rest of the pan.
Add half of the sauce to the bottom of a roasting dish and spread it out. Lay 3 of the lasagne sheets on top.
Add the meatballs on top and then pour over the rest of the sauce. Place the other 3 lasagne sheets on top of the meatball and sauce layer.
Add the cream cheese, yoghurt, mustard and a pinch of salt and pepper to a bowl and stir until smooth. Spread the mixture on top of the lasagne sheets. Sprinkle over the grated cheese and loosely cover the top of the dish with foil.
Place the lasagne into the oven for 20 minutes. Remove the foil and cook for a further 10 minutes. The lasagne will be ready when you can push a knife into it and feel that the pasta is soft and not crunchy. If you would like a little more colour on top, you can pop it under the grill for a few minutes until the cheese is bubbly and brown. Top with torn basil leaves if you like, and serve with a mixed salad.