For the Lasagna:

1. Preheat the oven to 180℃
2. Heat the oil in a medium sized pot; sweat the onions and garlic for 5 minutes over a low heat.
3. Add the mince and brown for a further 5 minutes.
4. Add the chopped tomatoes, tomato paste, beef stock, rosemary and sugar and simmer gently for 30 minutes. Season the mince with salt and pepper.
5. Melt the butter in a small saucepan, add the flour and cook for 2 minutes.
6. Slowly add the milk a little at a time, whisking continuously – making sure there are no lumps.
7. Bring to a gentle simmer and simmer for 2 minutes, season to taste. Set aside.
8. Bring a large pot of water to the boil and boil the lasagna sheets for 2 minutes. Drain and set aside.
9. Place half the mice into an oven-proof casserole dish, top with half the lasagna sheets, spoon over half the white sauce, repeat this process and top with grated Parmesan.
10. Bake the lasagna for 30 minutes at 180°c, until lasagne sheets are cooked through and golden brown on top.