Tomato and watermelon gazpacho

• 2kg ripe tomatoes (about 20), peeled and roughly chopped (1.9kg net)
• 5 cloves garlic, peeled and roughly chopped 
• 6 celery stalks, pale parts and leaves, all roughly chopped (450g net)
• 1 small onion, roughly chopped (140g net)
• 400g watermelon flesh, seeds removed
• 100g crustless white bread, broken into small chunks
• 150ml tomato passata (or tomato juice)2 tbsp red wine vinegar 
• 200ml olive oil, plus extra for drizzling 
• 15g basil leaves
• Coarse salt and black pepper

Croutons

• 150g crustless white bread, broken into 2-3cm chunks
• 3 tbsp olive oil 
• 1½ tbsp red wine vinegar 

1. First make the croutons. Preheat the oven to 180C. Place the bread in a medium bowl along with the oil, vinegar and 1 teaspoon of salt. Place a griddle pan on a high heat, add the croutons and cook for 2 minutes, turning until all sides are slightly charred and starting to crispen. Transfer from the pan onto a baking tray and place in the oven for about 12 minutes, until golden brown and crispy. Set aside to cool. 
   
2. Place the tomatoes, garlic, celery, onion, watermelon, bread, passata and 10 grams of basil in a blender or large bowl along with 1½ teaspoon of salt and a good grind of black pepper. Blend until smooth and then, with the blender still going, add the vinegar and olive oil. Refrigerate until needed. 
   
3. To serve, pour the soup into individual bowls and top with the croutons. Tear the remaining basil and sprinkle it on top of each portion, along with a final drizzle of oil. Finish with a little sea salt and serve at once.