01 - Preheat oven to 350°F (180°C).
02 - Lightly brush each barley rusk with olive oil using a pastry brush. Arrange on a baking tray and bake for 5-8 minutes until golden, crisp, and fragrant.
03 - While the rusks toast, combine the finely diced tomatoes, half of the chopped oregano, and a pinch of freshly ground black pepper in a mixing bowl. Toss gently to combine.
04 - Remove the rusks from the oven and allow them to cool slightly on the tray.
05 - Spoon the tomato mixture generously onto each rusk. Layer crumbled feta cheese over the top.
06 - Scatter red onion slices, pitted Kalamata olives, capers (if using), and the remaining fresh oregano over each rusk.
07 - Finish with an extra drizzle of olive oil and a final crack of black pepper. Serve immediately while the rusks are still crisp.