Tart London: How to make slow-roasted tomato sauce

It’s impossible not to fall in love with England when you’re in the countryside on an Indian summer’s day, with the glorious colours, light and a magical feeling of seasonal change in the air. We’ve been working from Jemima’s place in Somerset this month and enjoying the end-of-summer glut.

Fruit and vegetables are still in abundance in the bramble-filled garden. We have been harvesting a bounty of courgettes, apples and tomatoes, feeling like ancient pagans preparing to nestle down for the winter. There’s a sense of great joy you get from growing your own produce. It gives you a profound respect for — and understanding of — an ingredient. Seasonal vegetables, freshly harvested, are the best you can eat, packed with flavour and vitamins.

As summer dips into autumn, tomatoes are at their finest: full and heavy, in magnificent shades of red, orange and yellow. The idea of preparing yet another caprese salad or chilled soup no longer appeals. When there’s a nip in the air, we crave something a little warmer and heartier. We do this by roasting huge trays of tomatoes, of all shapes and sizes, with garlic, herbs, olive oil and chilli. Slow cooking this way allows the natural sugar in the fruit to caramelise; it also makes for the most delicious of sauces. So gather up as many ultra-ripe tomatoes as you can find from farmers’ markets or your greengrocer, and savour them throughout the autumn by roasting and jarring. They’re perfect for when you come home late from work and want a quick-fix pasta dish, or a base for curry or soup. You’ll find it difficult to ever open a tin again.

100ml olive oil

1 small onion, diced

8 garlic cloves, thinly sliced

1 tsp dried chilli flakes

1 tbsp fresh rosemary, chopped

Medium bunch of basil

2kg tomatoes (a mix of big, small and on the vine), halved

2 tsp caster sugar

Salt and pepper