1 1/2pounds chicken breast halves, boneless and skinless, cut into 2-inch pieces
3tablespoons olive oil, divided
1medium onion, chopped
1(14.5-ounce) can low-sodium chicken broth
2sweet potatoes, cut into 1-inch chunks
1bunch (about 1/2 pound) collard greens, rough-chopped into 2-inch pieces
1/2pound cooked smoked sausage, such as kielbasa, sliced into 1/2-inch thick rounds
Place 3 tablespoons flour in a large bowl, season with salt and pepper, add chicken pieces and toss gently to coat.
Heat 2 tablespoons oil in a 5-quart Dutch oven or heavy-bottomed pot over medium-high heat. Add chicken, reduce heat to medium and cook until browned, 10 minutes, turning occasionally. Transfer chicken to a plate.
Add remaining oil to pot over medium heat. Add onions to pot and cook, stirring occasionally, until translucent and just beginning to brown, about 3 to 4 minutes.
Increase heat to high and add chicken broth and 3/4 cups water to pot. Scrape up any browned bits. Return chicken to pot and add sweet potatoes and smoked sausage. Bring to a boil, reduce heat, cover and simmer 5 minutes. Make a paste with the remaining 1 tablespoon flour and 3 tablespoons water. Uncover, whisk in flour and water mixture and continue to simmer until chicken is cooked through, potatoes are tender and liquid has thickened, 5 to 6 minutes.
Stir in collard leaves and simmer 2 minutes more. Serve immediately, with cornbread and hot sauce on the side.