Preheat the oven to 190ºC (375ºF)
Heat the oil in an ovenproof skillet or casserole pan over a medium heat. Brown the mince and the chorizo until the mince is a deep golden brown and the chorizo has rendered its fat. *See notes
Add the onion, garlic and the Italian seasoning to the mince and the chorizo. Let the onions and garlic soften in the fats of the meat. Once the onions and garlic are soft and fragrant pour in the stock (or water) and the passata (or crushed tomatoes). Bring the sauce for a gentle simmer. Taste and adjust the seasoning.
Add the lasagna sheets to the sauce and cook uncovered for about 15 - 20 minutes, checking the pasta and stirring occasionally to make sure the noodles aren't sticking to the bottom of the pan.
While the pasta is cooking, mix the mascarpone with the egg and cheeses. Once the noodles are cooked, dollop the mascarpone mixture onto the pasta and cover it with the remaining mozzarella, and place in the preheated oven for 15 minutes, or until the cheese is golden and bubbling. Sprinkle with the basil leaves and extra parmesan.