Next level tomato soup

Heat the oven to 200C/180C fan/gas 6. Line a large, shallow roasting tin with baking parchment and arrange the tomatoes in the tin, cut-side up. Season generously with salt, then scatter with the garlic, chilli (if using), 1 tsp of the sugar and the oregano. Drizzle with 1 tbsp of the vinegar and 1 tbsp of the olive oil. Roast for 45 mins until the tomatoes are shrivelled and have released plenty of juice.

If making the croutons, tear the bread into small pieces and tip onto a baking tray. Drizzle with 2 tbsp olive oil and scatter with the parmesan, if using. Toss to coat the bread in the oil and cheese. Bake alongside the tomatoes for 20-25 mins, tossing a few times until golden and crunchy. Remove from the oven and set aside to cool. Will keep in an airtight container for a day.

Meanwhile, set aside a large handful of basil leaves, reserving the stalks and remaining sprigs. Heat another 2 tbsp olive oil in a saucepan or frying pan over a medium-low heat and cook the onions with a little salt for 20 mins until soft and sticky. Stir in the rest of the sugar, then pour over the remaining vinegar. Bring to the boil, then simmer for 3-5 mins until the onions have broken down a little and the liquid is syrupy.

Tip the tomatoes, along with their roasting juices, into the pan with the onions, then pour in the stock and scatter over the basil stalks and whole sprigs. Stir well and bring to the boil, then reduce the heat and simmer for 20 mins until the tomatoes have broken down into a chunky sauce. Remove from the heat and leave to cool slightly, then tip everything into a food processor or blender and blitz until the soup is as smooth as you like. Or, use a hand blender (you may need to blitz the soup in batches). For an even smoother soup, you can pass it through a sieve, if you like. Once completely cool, the soup will keep chilled in a non-metallic airtight container for up to three days or frozen for up to three months.

Crush the reserved basil leaves with a pinch of salt to a paste using a pestle and mortar. Stir this into the remaining olive oil to make a bright green basil oil. Tip the soup into a clean pan and reheat until piping hot, then ladle into bowls. Drizzle with the basil oil, then scatter with the cheesy, crunchy croutons, if using.