Drain the Kalamata olives, green olives, and capers thoroughly. Add them to the bowl of a food processor along with the roughly chopped garlic. Check that no olive pits remain. Excess brine can make the finished spread watery and overly salty.

Add the lemon juice, 1 tablespoon (15 ml) extra-virgin olive oil, dried oregano, and black pepper. Pulse the mixture 6–10 times, stopping to scrape down the sides as necessary. The finished tapenade should be finely chopped and moist enough to spread, with small visible pieces of olives. Avoid processing continuously, which can turn the mixture into a smooth paste. If it looks too loose, stir it and allow any excess liquid to settle before spreading.

Slice both ciabatta rolls horizontally if they are not already split. Lightly brush the cut surfaces with the remaining 1 teaspoon (5 ml) extra-virgin olive oil. The oil should form a thin coating rather than soak into the bread.

Heat a large skillet or grill pan over medium heat. Place the ciabatta halves cut-side down and toast for approximately 2–3 minutes, or until the surfaces become lightly golden and crisp. Work in batches if necessary, using approximately 5 minutes total for toasting. If the bread browns too quickly, reduce the heat slightly. Transfer the toasted bread to a cutting board with the cut sides facing up.

Divide the softened goat cheese evenly between the two bottom halves of the ciabatta rolls, using approximately 2 ounces (57 g) per sandwich. Spread it into an even layer, reaching close to the edges. The cheese should be soft enough to spread smoothly while remaining thick enough to hold the toppings in place.

Divide the prepared tapenade evenly between the two sandwiches, spreading it over the goat cheese. Keep the tapenade in a fairly even layer rather than piling it in the center. The goat cheese helps anchor the chopped olives and creates a creamy base beneath the vegetables.

Divide the tomato slices evenly between the two sandwiches, arranging them over the tapenade. Add the baby arugula, distributing it evenly over the tomatoes. If using the optional fresh basil, scatter the torn leaves over the arugula. Keep the vegetables in relatively flat layers so the sandwiches are easier to close and slice.

Place the top halves of the ciabatta rolls over the fillings. Press gently to help the ingredients settle without squeezing out the goat cheese or tapenade. Slice each sandwich in half using a serrated knife, if desired, and serve immediately while the bread retains its lightly crisp texture.