Preheat the oven to 160C fan/gas mark 4. Open out the pitta breads like a book and drizzle with olive oil, sprinkle over the oregano and season a little. Pop in the oven for 12-15 minutes until lightly golden and crisp. Leave to cool for 10 minutes, then break them up.
While the pitta are in the oven, make the dressing. Whisk or shake together 2 tablespoons of extra virgin olive oil, the pomegranate molasses and the juice of the lemon.
Peel and crush the garlic clove with the side of your knife and add it to the dressing. Season generously, whisk together then leave to one side. Pick the pomegranate seeds and keep to one side.
Roughly chop the tomatoes, trim and chop the cucumber (if you are using a large cucumber, halve it lengthways and scoop out the middle). Trim and finely slice the spring onions. Pick the parsley leaves and finely chop.
Trim and finely slice the radishes. Trim and roughly chop the cos or little gem. Toss everything together with the dressing (discarding the garlic) and spread out on to a platter. Scatter over the toasted pitta and the pomegranate seeds and sprinkle over the sumac, then serve.