1. Bring a large saucepan of water to the boil, add salt, bring back to the boil and add the linguine or spaghetti. 
2. Cook according to the instructions on the packet, until al dente. Drain well, reserving about 1 cup of the cooking water.
3. While the pasta is cooking, drain the canned tuna and place the tuna in a small bowl.
4. Add the chopped tomatoes, olives if using, lemon juice (use more lemon juice if you wish) and oil. Mash roughly with a fork.
5. Add ¾ cup of the cooking water to the tuna.
6. Tip the drained pasta into a large serving bowl and toss through the tuna sauce.

Tip: Semi-dried tomatoes are available in the deli at your supermarket. Use semi-dried as they are softer than dried tomatoes.