In a large pan or skillet, cook the ground turkey over medium-high heat, stirring often to break up the lumps until turkey is browned.
If using regular ground turkey, drain cooked turkey into a colander and blot with paper towels. Return drained turkey to pan. If using 99% fat-free turkey breast there isn’t any fat to drain. You can just blot it with paper towels.
Place onions in a microwave-safe bowl and cook in the microwave for 4 to 5 minutes until soft.
Add cooked onions to turkey. Stir in barbecue sauce, tomato sauce, and Worcestershire sauce. Bring to a boil; reduce heat to low and simmer uncovered for 25 minutes. Stir a few times while simmering.
Spoon the turkey mixture onto each sandwich thin or bun. If you have any leftovers, this mixture freezes great.