Arrange the tomatoes, cucumber, bell peppers and onions in a serving dish. Cut the cheese into 4 thick slices and add them to the dish. Drizzle the cheese with a little oil and top with olives.
Brush the pittas with oil, sprinkle with oregano and salt and press slightly to make the seasoning stick. Slice each pitta into 5-6 strips and place on a baking sheet lined with aluminium foil. Toast the pitta strips in the middle of the oven on the grill setting – turn them over after about 2 min.
Arrange the warm, toasted pitta strips on the Greek salad serving dish, garnish with oregano and serve – either as is or as a side dish with grilled meat or fish.