Whisk together the vinegar, garlic, lemon juice, Dijon, oregano, salt, and pepper. Using a Microplane, finely grate the clove of garlic over the vinegar mixture, then whisk to combine. Slowly whisk in olive oil until combined. Whisk or shake before serving.
For Greek Salad
In a large serving bowl, combine the lettuce, cucumbers, tomatoes, shallot, olives, and pepperoncini together. Add ¼ cup of dressing to the salad and toss to combine.
Dish out the salad into individual servings and top with croutons and crumbled feta cheese. Serve additional Greek Dressing on the side to add as desired.
Notes
Storage: You can prepare the salad up to 24 hours in advance. Just wait to add the croutons and dressing until ready to serve.Leftover Dressing: Store the leftover dressing for up to 2 weeks in the fridge and use it for salads or to marinate meat or veggies. Shallot Substitution: Feel free to use red onions in place of shallots--just soak red onion slices in cold water for 15 minutes to remove some of their sharpness.