1. Warm your oven to 200°C/Fan 180°C/Gas 6. Peel the potatoes. Slice them into chips about 1cm-thick and slide them into a large pan. Cover the chips with cold water and pop the pan on the hob. Bring the pan to the boil, then reduce to a gentle simmer. Cook the chips for 5 mins, then drain well. Se aside.
2. Meanwhile, halve the aubergines and score a cross-cross pattern onto the cut side of each half, cutting about 1cm deep. Arrange the aubergines, cut-side-up, in a roasting tin. Drizzle the aubergines with 1 tbsp oil and season with salt and pepper. Slide the aubergines into the oven and roast for 40 mins.
3. As soon as the aubergines go into the oven, pour 2 tbsp oil into a separate, large roasting tin and season with a good pinch of salt and pepper. Slide the tin onto a shelf below the aubergines to warm up for 5 mins. When the tin is hot, remove it from the oven. Carefully add the drained chips to the tin and use a spatula to turn them in the oil. Slide the chips into the oven and bake for 40 mins, turning halfway, till golden and crisp.
4. While the aubergines roast, make your piri piri sauce. Trim the tops off the chillies. Roughly chop them, removing the white pith if you prefer less heat. Peel and roughly chop the garlic. Pick the thyme leaves. Add the chillies, garlic and thyme to a small food processor.
5. Squeeze in the juice from both lemons and pour in the cider vinegar (save the balsamic vinegar for the next step). Add the smoked paprika, dried oregano and 1 tbsp sugar from your cupboard, if using. Season with a pinch of salt and pepper. Switch on the processor. Whizz the sauce till well combined and smooth, then pour into a small bowl. No processor? Finely chop the chillies and thyme leaves, grate or crush the garlic, and mix with the remaining ingredients to make a chunkier sauce.
6. Halve the cherry tomatoes and slide them into a salad bowl. Roughly chop the parsley and add to the tomatoes. Pour in 1 tbsp balsamic vinegar and 1 tbsp oil. Sprinkle over the pumpkin seeds and toss to combine.
7. When the aubergines have roasted for 40 mins, remove the tin from the oven. Spoon most of the piri piri sauce over the aubergines (save a few spoonfuls
for serving) and use a brush to evenly distribute it. Slide the aubergines back into the oven and roast for a further 10 mins.
8. Transfer the cooked aubergines to a platter. Serve with the chips and remaining piri piri sauce on the side, for dipping, along with the tomato salad.
9. Get Ahead
You can make the piri piri sauce the night before you want to cook the aubergines, following steps 4 and 5. Store the sauce in a covered bowl in the fridge, ready to spoon onto the cooked aubergines.