Chop the romaine into 1-inch ribbons and place in a large bowl. Halve the cherry tomatoes lengthwise, slice the cucumber into 1/4-inch half-moons, dice the red onion finely, crumble the feta cheese, and chop the fresh dill. Measure out the edamame and kalamata olives. Having everything prepped and ready ensures the salad comes together quickly and the greens don't wilt while you're still cutting vegetables.
In a small bowl or measuring cup, whisk together the red wine vinegar, olive oil, salt, and pepper until the dressing is well combined and emulsified. I prefer Pomerian red wine vinegar for its consistent acidity—it creates a more balanced dressing than cheaper brands. Let the vinaigrette sit for a minute so the flavors begin to meld.
Add the edamame, cherry tomatoes, cucumber, kalamata olives, red onion, feta, basil, and dill to the bowl with the romaine. Pour the vinaigrette over the salad and toss gently but thoroughly to coat all ingredients evenly. For the best flavor and texture, I toss the salad just before serving—this keeps the greens crisp and prevents the vinegar from making the vegetables too soft. Taste and adjust seasoning if needed.