In a large Dutch oven or heavy pot set over medium heat, cook the bacon, stirring occasionally until crisp, about 5 minutes. Use a slotted spoon to scoop out the bacon and transfer to a paper-towel-lined plate. Reserve the bacon fat in the pot and continue to heat over medium heat. Add the lima beans, corn, broth, onions and garlic, and bring to a simmer. Cook until the vegetables are heated through, about 15 minutes. Stir in the kale and cook until the kale begins to wilt, 3 to 5 minutes, and then add the butter, reserved bacon and some salt and pepper to serve.