Remove outer wilted leaves from romaine. Cut each head lengthwise into quarters, then crosswise into bite-size pieces (about 1–1½ inch). Rinse thoroughly in cold water, spin or pat dry, and transfer to a large serving bowl.

Chop vegetables

Core and dice the tomatoes into roughly 1-inch pieces. Peel (optional) and thinly slice the cucumber into half-moons. Peel and thinly slice the red onion into rings or half-rings. Roughly chop the parsley.

Assemble salad

Add the tomatoes, cucumber, red onion, black olives, and parsley to the bowl with the romaine. Sprinkle 1 tsp salt and 1 tsp black pepper over the vegetables and gently toss to combine so seasoning distributes evenly.

Dressing

Mince garlic

Peel and finely mince the garlic clove (or grate it).

Emulsify dressing

In a medium bowl or jar, combine the minced garlic, red wine vinegar, lemon juice, Dijon mustard, honey (or sugar), dried oregano, ½ tsp salt and 1/4 tsp black pepper. Whisk or shake to combine. Slowly stream in the 1/2 cup extra-virgin olive oil while whisking continuously until the dressing emulsifies and thickens slightly. Taste and adjust seasoning (add a little more vinegar or honey if needed).

Dress the salad

Just before serving, drizzle about half of the dressing over the salad and toss gently to coat evenly. Taste and add more dressing as desired. Serve family-style with the remaining dressing on the side for guests to add more.