- In very large resealable bag, combine ketchup, water, garlic sauce, brown sugar, vinegar and mustard.
- Add turkey thighs and seal bag; massage to coat well. Refrigerate for at least 1 hour or up to 24 hours.
- Place thighs and marinade into large roasting pan.
- Cover and bake in preheated 400°F (200°C) oven for 30 to 45 minutes.
- Uncover and turn over thighs. Return to oven and bake for about 15 minutes or until juices are no longer pink and instant read thermometer registers 165°F (74°C).
Slow Cooker Variation:
- Combine marinade ingredients in bowl and set aside.
- Place turkey thighs on greased grill over medium high heat and grill for about 10 minutes.
- Turn over and reduce heat to medium.
- Grill and brush with sauce liberally for 20 to 30 minutes or until juices are no longer pink and nstant read thermometer registers 165°F (74°C).
- Place marinated turkey thighs and marinade into 5 or 6 quart (4 or 5 L) slow cooker.
- Cover and cook on Low for 10 to 12 hours or on High for 6 to 8 hours.
Serve with salad and rice, gluten-free noodles or leftover mashed potatoes.