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 to 8 minutes until golden, crisp, and fragrant.
03 - While the rusks toast, combine the diced tomatoes, half of the chopped oregano, and a pinch of 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 evenly over each rusk. Layer generously with crumbled feta cheese.
06 - Top with sliced red onion, Kalamata olives, capers if desired, and the remaining fresh oregano.
07 - Finish each rusk with a light drizzle of olive oil and an extra crack of black pepper. Serve immediately while still crisp.