Soak wooden skewers in water for 30 minutes.

For the marinade: in a mixing bowl, whisk the coconut milk, oil, garlic, ginger, coriander, cumin, cardamom, cinnamon, and cayenne. Set aside.

Cut the chicken breasts into 32 cubes, about 3/4-inch each; add to the marinade and mix well to coat. Let stand at room temperature for 15 minutes. Alternately thread 4 pieces of chicken and 3 grapes onto each of eight 8-inch bamboo skewers.

Grill skewers over high heat until the chicken is firm and cooked through, 3 to 5 minutes each side. Transfer skewers to plates or a platter and sprinkle with salt and fresh herbs.