In a large pot or Dutch oven, heat the olive oil over medium high heat. Add the onions and sauté 4 minutes, until translucent. Reduce the heat to medium, add the garlic, oregano, cumin, garlic powder, black pepper, and cayenne (optional), and sauté for 30 seconds. Stir in the sweet potatoes, then add the vegetable broth, beans, and kosher sea salt and bring to a simmer.
Once boiling, reduce to a simmer and simmer 15 minutes until the sweet potato is tender. While simmering, roughly chop the kale. Thinly slice the green onions and radishes.
When the sweet potatoes are tender, remove from the heat and stir in the kale, green onions, and lime juice. Allow to cool slightly before serving. Taste, and if desired add additional kosher sea salt to taste. Serve garnished with radishes, a small dollop of Greek yogurt (optional), and hot sauce.