Directions:

Make Vinaigrette:
Whisk together all vinaigrette ingredients in a small bowl until combined well.

Make Salad:
Bring water, vinegar, sugar and salt to a boil in a 1-quart heavy saucepan, then add onion and simmer until crisp-tender, about 3 minutes. Drain and cool.

Spread romaine on a large platter and scatter with parsley, peppers, artichokes, olives, peperoncini, tomatoes and onion. Whisk vinaigrette again and drizzle over salad.