Make this in summer when tomatoes in season and at their best value — get the best you can — and try to mix a couple of different types for colour and taste. Method Preheat oven to 220°C (fan). Slice the tops off the peppers and remove the stems, seeds and white membranes from inside.
Rinse and put the whole peppers on an oven tray lined with baking parchment. Roast for about 40 minutes. When most of the skin is charred or deep golden, and the flesh softened, place on a colander or sieve over a bowl, cover with cling film, and when cool enough to handle, remove the skins.
Slice lengthways into 1cm-thick strips and return to the colander or sieve over the bowl to drain for a further 10 –15 minutes. Toast the bagel halves, then leave to dry until you prepare all the other ingredients. They should be crunchy outside and a little soft within.
Break into bite sized chunks. Wash the tomatoes, halve or dice them depending on the size, and place into a large salad bowl with the olives. Add the sliced roasted peppers, olives and a few basil leaves.
Soak the red onion in a small bowl of cold water with a pinch of salt for about 20 minutes - this reduces the sharpness of the raw onion, making it easier to digest. Drain and add to the tomatoes. To make the dressing: crush the anchovy fillets (if using) with the crushed garlic, red wine vinegar, 4 tbsp of the olive oil, 1⁄2 tsp of sea salt and a good pinch of black pepper.
Stir well and add to the tomato mixture, stir again, cove.