Cooked the spaghetti according to packet instructions.
Meanwhile, mix together the tuna, chilli, lemon juice, olive oil and capers. Taste for seasoning.
Drain the spaghetti and return it to the hot saucepan.
Toss through the tuna mixture.
Place a handful of rocket leaves(arugula) on each plate or bowl, and place the spaghetti mixture on top. The heat of the spaghetti will wilt the rocket leaves (arugula).