This easy salad is inspired by one of Ruby Tandoh’s – we ate versions of it on repeat through a ridiculously hot summer, braving 35°C in the kitchen to grab the watermelon and cucumber before retreating to the front room to sit in front of a fan. Chaat masala is one of my favourite cheat ingredients: it gives you bags of flavour all in one spice blend. You can buy it in larger supermarkets, or in a packet at your local Asian grocery shop (and once you have it, you can use it for the crispy masala chickpeas, lemon dal & pitta chips on page 70 of The Green Cookbook). Serve alongside a barbecue, or as part of a selection of sharing plates.