Place the romaine, cucumbers, shallot, cherry tomatoes, olives, and capers in a large salad bowl.

In a jar or small container, combine the olive oil, lemon juice, red wine vinegar, Dijon mustard, garlic powder, oregano, salt, black pepper, and red pepper flakes. Cover and shake until well combined.

Pour the dressing over the salad and toss to coat. Serve immediately.

For a more substantial salad, top with crumbled feta cheese or cooked salmon.