Preheat your oven to 200°C/Fan 180°C/Gas 6. Scrub the sweet potatoes and cut them into chips as thick as your finger (no need to peel them). Scatter the chips onto a baking tray. Drizzle over 1 tbsp olive oil and season with a pinch of salt and pepper. Toss to coat, then slide the chips into the hot oven and roast for 20 mins.

Slice the tomatoes into thin wedges and arrange them on a second baking tray. Slide them onto the shelf below the sweet potato chips and roast for 20 mins, till soft and slightly caramelised.

Pick the chervil leaves and pop them in a small bowl. Peel and finely chop or grate the garlic. Add the garlic to the chervil. Grate in the lemon zest and squeeze in the juice from 1 half. Pour in 1 tsp olive oil and add a little salt and pepper. Set aside.

When the sweet potato chips have cooked for 20 mins, carefully turn them over. Return to the oven and roast for 15-20 mins, till golden.

When the tomatoes have roasted for 20 mins, take them out of the oven and tip onto a chopping board. Roughly chop them into small pieces, then slide the tomatoes into the bowl of herbs and stir. This is your salsa.

Pour 1 tbsp olive oil into a large frying pan and warm to a medium-high heat. Rub a pinch of salt and pepper into the pollack fillets. When the frying pan is hot, add the fish, skin-side down. Fry for 5 mins, till the skin is crispy, then carefully turn over and cook for 2 more mins, till the fish is cooked through.

While the fish is cooking, tip the rocket into a bowl. Drizzle with 1 tbsp balsamic vinegar and 1 tsp olive oil and toss to dress the leaves.

Pop the cooked fish onto a couple of plates and top with the roasted tomato salsa. Serve with the sweet potato chips and rocket salad on the side.