In a large bowl, toss the eggplant, bell pepper, zucchini, and red onion in a little sea salt and freshly ground black pepper. Spread the vegetables evenly onto two large baking sheets lined with parchment paper. Roast for 25-30 minutes, or until tender and browned, flipping after 15 minutes. When cooked, set aside to cool.
In a medium sauce pan, cover the farro with 3 cups of water, and bring to a boil. Then reduce the heat to medium low and simmer 25-30, or until just cooked but not mushy (al dente). (Or, use the brown rice setting of a rice cooker.) Drain the farro (there will likely be some excess cooking water), rinse with cool water, and gently shake out any excess liquid.
To make the dressing, in a medium bowl, combine the lemon juice, aquafaba, Dijon mustard, and cayenne pepper. Whisk well, and add sea salt and freshly ground black pepper to taste. Set aside.
In a dry saute pan over medium low heat, toast the pine nuts for about 5 minutes or until golden brown
To Assemble the Salad
To a very large bowl, add the farro, the cooled vegetables, and the garbanzo beans, and toss gently to combine. Add the green onion, pine nuts, Kalamata olives, basil and mint. Pour the dressing over the salad and toss gently to combine. Season with seat salt and freshly ground black pepper to taste.
Squeeze half of a fresh lemon (or more, to taste) over the salad, and serve at room temperature.