Whisk together red wine vinegar, water, sugar, and salt until the salt and sugar are dissolved.
Pack the thinly sliced red onion into a mason jar or a small, non-reactive bowl just big enough to hold the onion. Pour liquid over the onion and let sit at room temperature for an hour. These can be made up to a week in advance and stored in the refrigerator.
Mix all the dressing ingredients together.
Dress the greens and sugar snap peas. Top with pickled red onion, fresh herbs, crumbled potato sticks or chips, blue cheese, black pepper to taste and, last but not least, the steak.
4 servings