Season chicken with salt, pepper and cider vinegar and set aside while you prepare remaining ingredients.
Heat a large skillet over medium-high heat and add 2 tbsp oil. Brown chicken, in batches, about 3 minutes per side, until golden brown. Remove browned chicken and set aside on a plate. Add onion and poblano pepper to skillet and toss occasionally, until onion is softened, about 5 minutes. Add garlic and cumin and continue to toss, until fragrant but not burnt, about 2 minutes more.
Add chicken back to pan along with white beans, chicken broth and bay leaf. Bring to a boil, reduce to simmering and cover. Simmer until chicken is cooked through and flavors are absorbed, about 12-15 minutes. Remove cover, add kale and toss until wilted, about 2-3 minutes.
Recipe by Jackie Ourman at http://jackieourman.com/braised-chicken-with-white-beans-poblanos-and-kale/