How to Make It
In a small bowl, combine the garlic, paprika, 1/2 teaspoon of the salt and the pepper; add 1 tablespoon of the olive oil and mash to a paste. Rub the paste on the ribs. Cover and let marinate at room temperature for 1 to 2 hours, or refrigerate overnight for a more garlicky flavor.
In a large enameled cast-iron casserole, combine the sliced rutabaga, pearl onions, water, vinegar, bay leaves and saffron with the remaining 1/2 cup of olive oil and 1/2 teaspoon of salt. Add half of the mixed greens, cover and cook over high heat until the greens wilt, 2 to 3 minutes. Add the remaining greens and cook, tossing, until wilted.
Cut the ribs into 2- to 3-rib pieces and add them to the casserole. Cover and cook over moderately high heat, maintaining a slow boil and stirring occasionally, until the ribs and rutabaga are tender, about 1 hour.
Scatter the sweet potato slices over the giambotta and cook, stirring occasionally, until softened, 10 to 15 minutes. Discard the bay leaves. Add the spinach and cook, stirring, until just wilted, about 1 minute. Serve hot.