Add the curry powder, turmeric, and Thai red curry paste to the onions and stir until onions are coated in the spices (about 1 minute). Add the chicken pieces to the pan, stirring frequently to prevent sticking and encourage stir-frying. Cook thoroughly (about 5-7 minutes) until chicken is cooked through and temps at 165 degrees Fahrenheit. Use tongs to remove chicken and transfer to a plate.