In a 5-quart Dutch oven or heavy pot with a lid, heat oil over medium-high. Season chicken with salt and pepper. Cook in two batches, until browned, 6 to 8 minutes, turning halfway through. Transfer to a plate.
To pot, add onion, and season with salt and pepper. Cook, stirring, until onion begins to brown, 3 to 5 minutes (reduce heat if browning too quickly). Add flour; cook, stirring, 1 minute. Add wine and chicken along with any accumulated juices.
Cover, and cook until chicken is opaque throughout, 8 to 10 minutes; stir in dried plums.