Method:
1 Preheat the oven to 200°C fan forced.
2 Heat oil in a frying pan over medium heat, sauté the onion and garlic for a minute until softened. Add the lamb and cook for 3-4 minutes until browned add the passatta and bring to the boil, simmer 3 minutes until thickened. Season with salt and pepper.
3 Melt the butter in a saucepan over medium heat, stir in the flour and cook for 1-2 minutes, slowly whisk in the milk, cook stirring until the sauce comes to the boil, season with salt and pepper and remove from the heat.
4 Bring a saucepan of salted boiling water to the boil, reduce to a simmer, blanch the lasagna sheets for 2 minutes, remove to a board with tongs. Add the spinach leaves to the boiling water and blanch for 1 minute, drain.
5 Place 1 lasagna sheet on a baking tray, top with a spoonful of mince mixture, white sauce and a spinach leaf, repeat layers. Spoon over white sauce sprinkle with parmesan, bake for 6-7 minutes until light golden and warmed through. Transfer to a plate and serve.