1. Heat the oven to 350°. Put the taco shells on a baking sheet and bake them until crisp, about 8 minutes. Break each one in half.
2. In a medium saucepan, heat 1 tablespoon of the oil over moderate heat. Add the beans, salsa, and 1/4 teaspoon of the salt. Cook, mashing with a potato masher, for about 5 minutes.
3. In a small glass or stainless-steel bowl, whisk together the vinegar, mustard, pepper, chili powder, and the remaining 1/2 teaspoon salt. Add the remaining 4 1/2 tablespoons oil, whisking. Add the cilantro.
4. To serve, spread one side of the taco-shell halves with the refried beans and put four on each plate. Top with layers of the lettuce, tomatoes, avocado, cheese, chicken, and olives. Pour the dressing over the salads.
Wine Recommendation: The forceful flavor of cheddar cheese and the saltiness of the olives will go very nicely with a crisp and lively sauvignon blanc from California.