For the steak, rub the steak in olive oil and season well. Heat a griddle pan until smoking hot and griddle the steak for 3-4 minutes each side. Set aside and leave to rest for three minutes.
For the chips, dry the potato chips in a clean tea towel. Place the vegetable oil into a deep, heavy-based saucepan and heat until a small cube of bread sizzles and turns golden-brown when dropped into it. (CAUTION: hot oil can be dangerous. Do not leave unattended.) Gently drop the potato into the hot oil. Deep fry for 3-4 minutes, or until lightly golden-brown and crisp.
Carefully remove the chips from the oil with a slotted spoon and drain on kitchen paper.
In a bowl, soak the courgette chips in milk for 3-4 minutes. Dredge in flour, then carefully drop into the hot oil. Deep fry for 5-6 minutes, or until golden-brown and crisp. Remove with a slotted spoon and drain on kitchen paper.
Carefully drop the potato chips back into the hot oil and fry for another five minutes to make sure they are really crisp and golden. Carefully remove with a slotted spoon and drain on kitchen paper. Sprinkle with sea salt.
To serve, place the steak on a serving plate and serve with the courgette and potato chips.