In a pot, bring salted water to a boil. Add the green beans and cook for about 3-5 minutes until bright green and tender-crisp. Drain and rinse under cold water to stop the cooking process.
In a mixing bowl, combine the tahini, lemon juice, minced garlic, and maple syrup (if using). Whisk until smooth. Adjust the consistency with a little water if needed; it should be pourable. Season with salt and black pepper to taste.
In a large bowl, combine the romaine lettuce, spinach, kidney beans, and cooled green beans. Pour the tahini dressing over the salad and toss gently to combine, ensuring all ingredients are well coated.
Finish by sprinkling chopped cilantro over the top and serve with lime wedges on the side for an added burst of flavor. Enjoy your bright and healthy salad!