Melt the butter with 1/2 tbsp oil in a frying pan, and add the gnocchi. Cook over a medium heat, stirring regularly, until crispy and golden brown (around 10 minutes). Remove the gnocchi from the pan, and set aside.

Heat the remaining 1/2 tbsp oil in the pan, and add the broccoli and leek. Cook for a few minutes over a medium heat until the leek is soft. Add the vegetable stock, and simmer for until most of the excess liquid has evaporated. Add the asparagus, halved tomatoes and garlic, and cook for a few more minutes.

When the vegetables are fairly soft, return the cooked gnocchi to the pan. Add the sweetcorn, creme fraiche, ricotta and grated cheese, and mix well until the cheese has melted to give a smooth sauce.

Season generously with black pepper, and serve with fresh parsley.