Preheat oven to 190 degrees C. Lightly grease a 2 litre casserole dish.
Bring a large pot of salted water to a boil, add penne pasta and cook 10 minutes or until al dente; drain.
Heat the oil in a large wok or frypan over medium-high heat. Mix in onion and cook 5 minutes. Stir in the celery and capsicum and continue cooking for another five minutes. Mix in the garlic, salt and pepper and continue cooking 3 minutes. Pour in sherry; stir in the kale and cover. Reduce heat to medium and cook for 5 minutes, stirring occasionally, until the kale has wilted.
Transfer wok mixture to a large bowl. Mix in the cooked pasta, soup, vegetable stock and tuna. Pour mixture into the prepared casserole dish. Top with a layer of mozzarella followed by a layer of bread crumbs. Bake uncovered in the preheated oven for 25 minutes.