1. Preheat oven to 190°C. Lightly grease a 6cm deep, large ovenproof dish.
2. Cook penne as directed on the pack. Meanwhile, heat oil in a large, deep-sided frying pan over a medium heat. Add mushrooms and cook 10 minutes or until soft, stirring occasionally.
3. Add sugo, basil and chilli flakes to mushrooms and bring to the boil. Place sour cream and cornflour in a small bowl and mix to combine; add to sugo mixture. Reduce heat and simmer, stirring for 1 minute. Stir in tuna and parsley. Spoon into prepared dish.
4. Place breadcrumbs, Parmesan and butter into a bowl and stir until combined. Top tuna mixture evenly with breadcrumb mixture. Bake 25 minute or until golden.