In a bowl, mix together ground turkey, chili powder, salt, black pepper, and onion powder until well-blended. Stir in jalapeno, garlic, lime juice, and feta.
Shape ground turkey into patties.
Bring grill or grill pan to medium heat. Grill until internal temperature reaches 165, about 5-6 minutes per side. (Use an instant read meat thermometer in order to make sure that meat is thoroughly cooked without drying it out.)
While burgers are grilling, stir together all ingredients for cilantro lime sauce.
Place burgers on buns, top with cilantro lime sauce, tomato slices, and lettuce.
Serve immediately.
Recipe by A Kitchen Addiction at https://www.a-kitchen-addiction.com/chili-lime-feta-burgers-with-cilantro-lime-sauce-giveaway/