In a large pot, heat the olive oil over medium heat. Add the onion and a few pinches of salt and pepper, and cook until the onion is translucent, about 8 minutes.
Add the fennel, garlic, carrots, and thyme. Cook until the carrots begin to soften, 8-10 minutes, stirring occasionally. Add the cabbage and another pinch of salt and pepper, and cook until cabbage is soft, about 5 minute more.
Add the white wine, stir, and let the wine cook off, about 1 minute.
Add the broth, beans, and rind. Reduce the heat and let the soup simmer until the vegetables are tender, about 15 minutes. Add the kale and simmer for about another 5 minutes. Add the lemon juice then taste and adjust the seasonings. Discard the cheese rind and garnish with the fennel fronds.