For the dressing (makes about 3/4 cup):
1 cup loosely packed cilantro, washed, stems removed, and roughly chopped (about 3/4 bunch)
1/2 cup sour cream
2 tablespoons fresh lime juice (about 1/2 lime)
1 clove garlic
1/2 cup olive oil
2 teaspoons sherry vinegar
1/2 teaspoon kosher salt
A few grinds of freshly-ground black pepper
Water, to thin

For the salad:
2 1/4 cups shredded romaine lettuce
1/3 cup cherry tomatoes, sliced in half
1/2 cup cooked and cooled quiona, optional
1/2 cup black, kidney or pinto beans, rinsed and drained
1/4 cup shredded cheddar or pepper jack cheese
1/2 large avocado, diced
3 tablespoons sliced black olives
3 tablespoons finely-chopped green onions (from about 2 onions), light green and white parts only
1/2 cup crumbled tortilla chips