Add garlic to blender or food processor. Chop until minced. Add rest of dressing ingredients (except for olive oil). Blend until all ingredients are pureed.
On a low speed, slowly drizzle in extra virgin olive oil. Once blended, you can serve or refrigerate.
Cut romaine in half lengthwise. Brush with olive oil. Grill each half cut side down on a hot grill until the lettuce begins to char, usually about 45 seconds to a minute. Remove immediately, top with dressing and serve.