Rachel Roddy’s ratatouille and potato gratin recipe | Stew

We swapped the heatwave and melting pavements in Rome for a similar situation in London, which meant catching a train to Dorset felt something of a relief. Not that it wasn’t hot there too, but it was offset by the sea, a garden and a dark, cool house. The weather also meant that the always good July produce was superb and abundant: all the berries, cherries, peas, runner and french beans; but also potatoes, aubergines, courgettes, tomatoes and herbs – all of which go into this week’s recipe.

My template for ratatouille is a mix of Jane Grigson’s recipe in her Vegetable Book and Robert Carrier’s version in Great Dishes of the World, plus the advice from a French friend to cook the aubergine separately, either by deep-frying (by far the tastiest option), baking, or air frying. The benefit of this step is not just flavour; it ensures the aubergine holds its shape better, meaning distinct chunks in the final stew.

What I like about Grigson’s recipe is the initial lively simmer (with a lid on), which kickstarts the cooking, followed by an uncovered simmer, then a final livelier simmer so any wateriness disappears. You will have a good idea of how sweet or acidic the tomatoes are from tasting them raw, but taste again towards the end of cooking and, if necessary, add a pinch of sugar or jot of red-wine vinegar.

Ratatouille is a Provençal word, which, according to the digital dictionary Orthodidacte, is linked to two terms: tatouiller, which means “to handle repeatedly” or “grope,” as well as “to stir in water’; and ratouiller, which means ‘to stir in water,” “mix for a long time,” or “stir up the mud at the bottom of the water”. I am at a loss as to how “grope” can be applied here, but the rest of the terms can be applied in some way to the making of ratatouille, especially the stirring of the mud at the bottom of the water, which is a reminder to swirl the spoon deeply so the vegetables don’t clump and stick to the bottom of the pan.

Potatoes are delicious when simmered along with tomatoes until soft, but their addition does turn it into another dish, which is why I have called this ratatouille and potato gratin – the gratin being a topping of soft breadcrumbs, grated cheese, minced herbs and olive oil, which, under the grill, turns into a crusty top.

If you are eating straight away, let the dish sit for about 10 minutes, so the juices that have run free are reabsorbed, before serving with sausages, grilled cheese, slices of roast chicken or simply a green salad. While the top will lose some of its crusty edge, the dish is just as good and even more velvety at room temperature.

Ratatouille and potato gratin

Serves 4

1 large aubergine, cut into 2cm chunks
Olive oil
Salt
1 large onion, peeled and sliced
1 garlic clove, peeled
2 courgettes, cut into chunks
1 red or yellow pepper, cut into chunks
1 all purpose large potato, peeled and cut into chunks
3 big tomatoes, peeled, or 1 x 400g tin tomatoes
Sugar and red-wine vinegar (optional)

For the topping
100g of soft breadcrumbs
2 tbsp grated parmesan
2 tbsp minced herbs (parsley, thyme, marjoram, say)

Either deep-fry the aubergine chunks until golden, or spread them on a baking tray, rub them with oil and salt and bake for 25 minutes, until soft and golden, or use an air fryer. Set aside.

In a heavy-based pan, warm four to six tablespoons of olive oil and the onion and garlic. After about five minutes, add the courgettes, peppers and a pinch of salt, and stir. Five minutes later, add the potato and tomato, cover and simmer for 20 minutes.

Check the amount of liquid and add a little water so that the vegetables are surrounded, then reduce to a simmer for 40-45 minutes, stirring every now and then.

Ten minutes before the end of cooking, raise the heat a little so wateriness bubbles away for a dense stew. Then, in the last minutes of cooking, stir in the aubergine and taste for salt, adding a jot of sugar or red-wine vinegar, if you wish. Leave to cool a little.

Tip the stew into a roughly 30cm x 20cm rectangular dish. Combine the topping ingredients with some olive oil, then spread the crumbs over the top of the ratatouille and put under the grill for a few minutes, until the top is crusty.