Fill your kettle and boil it. Fill a large pan with the hot water, topping it up with a little more water if you need to. Add a good pinch of salt, pop on a lid and bring back to the boil.

While the water comes to the boil, peel and finely chop the garlic. Halve the chilli and scoop out the white seeds and pith (or leave them in for a spicy kick). Finely chop the chilli. Finely grate the zest from the lemon. Halve the cherry tomatoes.

The water should be boiling by now. Add the spaghetti and simmer for 8-9 mins, till the pasta is cooked and tender but still with a bit of a chew.

While the pasta simmers, put a frying pan on a medium heat for 2 mins. Add 1 tbsp olive oil and the garlic, chilli and lemon zest. Sizzle, stirring, for 30 secs. Add the cherry tomatoes and fry, stirring often, for 3 mins till they start to soften.

Tip the fish pie mix into the pan. Gently stir. Fry for 5 mins, turning the fish pieces once, till they are opaque and flake easily when pressed with a fork. Take the pan off the heat if the spaghetti isn't quite ready yet.

When the spaghetti is cooked, scoop a mugful of water out of the pan (mind your fingers as you scoop the water, or use a ladle). Drain the spaghetti. Tip the spaghetti into the pan with the fish. Add half the rocket. Pop the pan back on the heat, add 100ml of the pasta water and gently toss the spaghetti, rocket and fish together. If it seems a little dry, add a splash more water.

Squeeze the juice from half the lemon into the pan. Taste the fish and add a pinch of salt or pepper if you think it needs it. Divide between 2 warm plates. Top with the remaining rocket and serve with the remaining lemon sliced into wedges for squeezing.