This recipe is just as good cold as it is hot, so use any leftovers to make packed lunches. This is designed to be a low cost recipe.
Bring a large saucepan of water to the boil and add a generous pinch of salt. Cook the pasta according to packet instructions. Once cooked, drain and transfer to a large serving bowl.
Mix the olive oil into the cooked pasta and season with salt and pepper. Stir through the tuna and add the zest of the lemon along with the juice of half of the lemon.
Just before serving toss through the rocket leaves.