Place the beans, tomato, bell pepper, corn, onion, jicama, jalapeno pepper, and feta cheese in a large salad bowl.
Mash the garlic and salt together with a mortar and pestle. Whisk together the mashed garlic, lime juice, mustard, and pepper in a small bowl. Add the oil in a slow, steady stream while whisking. Continue whisking until smooth. Drizzle the dressing over the salad and toss to coat. Chill overnight.
