Rachel Roddy’s ratatouille and potato gratin recipe

The classic Provencal stew, but with potato for ballast and topped with a cheesy herb crumb

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.