Place flour on a plate. Dredge chicken in flour, shaking off excess.
In a Dutch oven, heat 1 tablespoon oil over medium-high heat. Working in batches, saute; chicken, turning as each side browns, until golden brown, about 5 minutes. Using a slotted spoon, transfer to a platter.
Add remaining tablespoon oil to pot. Cook onion and garlic, stirring frequently, until onion is softened, about 7 minutes. Add broth, tomato paste, olives, and orange zest; season with salt. Bring to a boil.
Return chicken to pot. Cover; simmer, turning chicken once or twice, until tender but not falling off the bone, about 20 minutes. Serve hot.