1. In a medium sized bowl, combine your ground chicken, chopped spinach and dill fronds, minced red onion and garlic, feta crumbles, Worcestershire sauce and salt and pepper.
2. Using your hands, gently work together your burger mixture, taking care not to over-work the meat.
3. Form your meat into four patties and brush liberally with olive oil to prevent them from sticking to the grill.
4. If you’re me, pass your burgers off to your husband for grilling. Otherwise, you want to grill the burgers over direct medium-high heat (about 400-450ºF) for 8-10 minutes, turning once about halfway. Be sure to keep the lid closed as much as possible. Unlike beef burgers, you want to make sure that your chicken patties are cooked through evenly but still juicy. Aim for an internal temperature is 165ºF.
5. While the burgers are grilling, gently mix together the ingredients for the feta and dill yogurt sauce, cut your roasted red peppers into thin slices, and set aside.
6. To assemble your burgers, spread a generous amount of yogurt sauce on both sides of your bun, stack on your chicken patty and roasted red peppers, and enjoy!