Easy Greek Salad

Ingredients (11)

• 1 medium head romaine lettuce, torn into bite-size pieces, washed, and dried
• 2 medium tomatoes, cored, seeded, and large dice
• 1 medium English cucumber, large dice
• 1 cup kalamata olives, pitted and halved
• 1/2 medium red onion, thinly sliced
• 3 tablespoons extra-virgin olive oil
• 2 tablespoons freshly squeezed lemon juice (from 1 medium lemon), plus more as needed
• 1 1/2 teaspoons finely chopped fresh oregano leaves or 1/2 teaspoon dried oregano
• 1/4 teaspoon kosher salt, plus more as needed
• Freshly ground black pepper
• 1/2 cup crumbled feta cheese (about 2 1/2 ounces)