Heat olive oil in a large skillet over medium heat. Saute onion and garlic in hot oil until onion softens, 5 to 7 minutes.
Increase heat to medium-high, add chicken to onion mixture, and cook and stir until chicken is no longer pink in the center and the juices run clear, 5 to 10 minutes.
Stir water, soy sauce, and Sriracha sauce into chicken mixture. Reduce heat to medium, cover the skillet, and cook for 30 minutes. Stir marmalade into chicken mixture, bring to a simmer, and cook until chicken is tender and falling apart, about 15 minutes more.
