Heat your oven to 200ºC/Fan 180ºC/Gas 6. Trim and dice the courgettes. Halve the chilli, flick out the seeds (hang on to them for our tip over there) and white bits for less heat. Finely chop it. Peel and crush the garlic.
Tumble the courgettes, chilli and garlic in a large roasting tin. Add the fish pie mix. Cut the lemon into 8 pieces and add them to the tin.
Season the fish and veg with black pepper and drizzle with 1 tbsp olive oil. Toss to mix. Place the roasting tin in the oven for 15 mins till the fish is just cooked through.
While the fish is cooking, tip the spaghetti into a pan. Fill the pan with boiling water. Simmer for 8-10 mins till it’s just tender with a little bite. Drain the spaghetti.
Divide the spaghetti between 2 pasta bowls. Pick the leaves off the parsley and roughly chop them.
Stir the parsley through the fish mixture then spoon over the spaghetti. Season to taste and serve with the cooked lemon wedges for squeezing.