For the vinaigrette:
4-6 tablespoons extra-virgin olive oil
2 teaspoons Dijon mustard
1 small shallot, minced
2 tablespoons red wine vinegar
1/4 teaspoon salt
Freshly ground black pepper, to taste
For the salad:
6 ounces romaine lettuce, washed, dried and torn into bite-sized pieces
2 small vine-ripe tomatoes, sliced
1 red or yellow bell pepper, cored, seeded and sliced
1 small red, white or sweet onion, thinly sliced
1 cup garbanzo beans, rinsed and drained well
6-8 brown mushrooms, brushed clean and chopped (optional)
Make the vinaigrette: Combine all dressing ingredients in a lidded glass jar, cover and shake vigorously to combine. Set aside until ready to use.
To assemble the salad, arrange lettuce, tomatoes, bell pepper, onion, beans and mushrooms in a serving bowl. Drizzle with vinaigrette and serve immediately.