In a bowl, mix Greek yogurt, garam masala, cayenne pepper, turmeric, cumin, coriander, paprika, lemon juice, minced garlic, ginger paste, salt, and white pepper until well combined.
Put the chicken breasts in a sealable plastic bag and pour the marinade over them, ensuring each piece is evenly coated. Seal the bag, squeeze out the air, and knead to ensure the chicken is fully marinated.
Refrigerate the chicken for at least 3 hours to let the flavors soak in.
Heat the grill to medium-high. Cook the chicken for about 6-7 minutes on each side, or until it reaches an internal temperature of 165°F (74°C).
Let the chicken rest for a few minutes after grilling. Serve with extra lemon and fresh herbs if desired.