Panzanella salad with slow roast tomatoes and pickled red onion

500g mixed tomatoes

2 tbsp olive oil

Sea salt and pepper

150g leftover sourdough

2 tbsp olive oil

½ cucumber

50g green olives, chopped in half

5 anchovies, chopped

Basil leaves, for garnish

For the pickled red onion:

2 small red onions, peeled

150ml red wine vinegar

50g caster sugar

Pinch sea salt