Heat the olive oil in a Dutch oven or a 3- to 4-quart soup pot over medium heat. Add the garlic and saute, stirring, until starting to brown, 2 to 3 minutes. Add the sun-dried tomatoes and stir to combine. Add the kale, tossing to coat it well with the oil. Season with the salt and a few grinds of pepper, and continue stirring until all the kale is wilted. Add the stock, bring to a boil, reduce to a simmer, cover and cook until the kale has softened, about 8 minutes. Uncover, turn the heat to high, and boil away the remaining liquid, stirring frequently, until the pan is almost dry. Take the pan off the heat. Season with the vinegar and stir to combine. Transfer to a small serving dish or plates. Top with the crumbled goat cheese, if you like.