01 - Preheat oven to 350°F (180°C). Line a baking tray with parchment paper.
02 - Lightly brush each barley rusk with olive oil using a pastry brush. Arrange on the prepared baking tray and bake for 5-8 minutes until golden, crisp, and fragrant.
03 - While the rusks toast, combine the diced tomatoes, half of the 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 for 2-3 minutes.
05 - Spoon the tomato mixture evenly over each rusk. Layer generously with crumbled feta cheese on top.
06 - Scatter red onion slices, Kalamata olives, capers (if using), and the remaining oregano over each rusk.
07 - Finish with a light drizzle of extra virgin olive oil and an extra crack of black pepper. Serve immediately while the rusks are still crisp.