1) Preheat oven to 180C/Gas 4.
2) In a medium bowl stir together ricotta, spinach, egg, cumin and salt and set aside.
3) In a large saute pan over medium-high heat add 3 tablespoons of oil and the butter and saute pork and cayenne pepper until meat is brown, about 5-7 minutes. Remove meat from the pan to a bowl and add mushrooms to the pan. Cook until tender, another 5 minutes. Add meat back to the pan, stir in 50g of the Parmesan, season with salt and pepper, to taste, then transfer mixture to a bowl and set aside.
3) To assemble, layer bottom of 30-by-20cm casserole dish with a third of the salsa, then six noodles, overlapping to cover the entire bottom surface of the dish. Next, evenly spread over the noodles half of the ricotta spinach mixture, followed by half the pork mushroom mixture and a layer of mozzarella. Layer another third of the salsa, six noodles, the remaining ricotta spinach mixture and the remaining pork mushroom mixture. To finish, add the last six noodles and top with the remaining salsa. Place the remaining mozzarella slices on top along with the remaining Parmesan. Finish with a drizzle of olive oil and pepper, to taste.
4) Bake covered for 45 minutes. Increase oven temperature to 220C/Gas 7, uncover and bake for 15 more minutes or until golden brown and bubbly.