Wash and pat dry 500g chicken breast fillets. Cut them either lengthways into strips or into coarse cubes. Thread onto 8 wooden or metal skewers.
Mix 1 finely diced onion with 2 tablespoon olive oil, 0.5 teaspoon cayenne pepper, and 1 pinch of cumin. Brush the mixture onto the chicken.
Heat a non-stick pan over medium-high heat without adding any oil or fat. Fry the skewers for 8 minutes, turning occasionally, until the chicken is cooked through (internal temperature should reach 74°C / 165°F).
While the chicken cooks, finely chop 2 stalks of mint. In a bowl, combine half of the 1 tablespoon roasted sesame seeds with the mint, 200g Greek yogurt, and 100ml coconut milk. Season with salt and pepper to taste.
Divide the sauce among 4 bowls and sprinkle each with the remaining sesame seeds. Serve with the skewers.