Heat oil in large skillet on high heat. Crumble in ground turkey. Cook 5 min., breaking up large pieces with wooden spoon. Drain excess fat. Stir in onions, peppers, chili powder and cumin. Cook 3 to 5 min., or until meat is browned and vegetables are softened.
Stir in Worcestershire sauce and 1/3 cup (75 mL) water, scraping browned bits from skillet. Stir in ketchup. Bring to a simmer, stirring occasionally, 8 to 10 min., until mixture is thickened.
Divide meat mixture over 4 half-rolls.
Substitute ketchup with barbecue sauce, if desired. Serve veggie sticks on the side.