Preheat the oven to 350°F.Heat a large Dutch oven medium-high heat and add the olive oil.Season the chicken with salt and cracked black pepper and add to the hot oil. Sear on all sides until golden brown, about 4 minutes per side. Remove the chicken and place on a plate.Remove any excess oil from the pan, leaving 2 tablespoons. Add the onions and garlic along with the fennel and red pepper flakes. Cook until onions are soft and translucent, about 4 minutes.Drain the tomatoes, reserving the liquid, and crush the tomatoes with your hands.First, add the tomato juice to the pot and cook for 2 to 3 minutes, scraping down the sides of the pan. Then, add in the beans and stir to coat. Next, stir in the tomatoes.Add in the kale and place the chicken pieces back into the pan, skin side up. Add enough chicken broth or water to come halfway up the chicken. Add the rosemary sprig and bring to a simmer.Place uncovered into the oven and cook for 25 to 30 minutes until the chicken is tender and cooked through. Divide evenly between 4 bowls.