2: Cut 250 g fresh tuna into chunks, then salt and pepper lightly.
3: Pour 2 tablespoons olive oil into a large frying pan on high heat. When hot, add the tuna chunks. Fry quickly, stirring frequently, until just starting to brown. They do not need to be cooked through. Set aside.
4: Using the same pan, pour in 2 tablespoons olive oil, then the chopped leeks. Cook very lightly, stirring from time to time. Salt and pepper after removing from the heat. Set aside.