This is a colorful and richly flavored salad that’s fun to serve—the purple potatoes really give the dish a surprising look.
Place the potatoes in a medium saucepan and add enough water to cover. Bring to a boil, reduce the heat to medium, and cook for about 10 minutes, or until tender when pierced with a fork. Drain the potatoes and let them cool. Once cooled, peel if desired and cut into ½-inch cubes.
Place the kale and tomatoes in a skillet or saucepan and sauté for 2 to 3 minutes, or until the kale has softened slightly. Add water 1 to 2 tablespoons at a time to keep the vegetables from sticking to the pan. Add ¼ teaspoon lime juice and let cool.
In a blender, combine the cilantro, garlic, tahini, salt, cayenne pepper, remaining lime juice, and 2 tablespoons water. Blend until smooth.
To serve, prepare a bed of the cooked kale and tomatoes in a large salad bowl, top with the boiled potatoes, and spoon the dressing over the top. Garnish with chopped cilantro, if desired.
NOTE: If you’d like an especially pretty salad, peel the potatoes; with the skins left on, the potatoes will be a bit harder to cut neatly but will still taste great.