In a large bowl, gently combine ground chicken, feta, garlic, red onion, herbs, lemon zest and juice, spices, salt, pepper, and olive oil.
Mix just until combined—do not overwork or burgers will be dense.
Shape into 4 equal patties.
Chill for 10 minutes if time allows (helps them hold together).
Heat a grill or skillet over medium heat.
Lightly oil the surface.
Cook burgers for 5–6 minutes per side, until golden and cooked through (internal temp 74°C / 165°F).
Rest for 2 minutes.
Serve on toasted buns with tzatziki sauce, cucumber, tomato, and lettuce, or as desired.
