Preheat oven to 180°C. Grease pie dish (approximately 30cm x 22 cm) with olive oil.
On a floured bench, roll out pastry to about ½cm thick. Lay pastry in prepared dish, ensuring it goes up the sides of the dish. Sprinkle with cheese.
Heat oil in a frying pan over medium heat. Add onion and garlic and cook, stirring regularly, until onion is soft. Add sausages and corn kernels and mix to combine. Tip into pie dish and spread evenly over pastry.
In a medium bowl, add eggs, cream, salt and Italian seasoning. Mix well then pour over sausage mixture.
Lay tomato slices on top and sprinkle with pine nuts.
Bake in oven for 50–60 minutes, until a knife inserted halfway between the centre and the outer edge comes out clean. Leave to stand for 10 minutes before serving.