How to make it
In a blender, combine shallots, lemongrass, ginger, turmeric, and half the oil and blend into paste.
In a dry pan over medium hear, lightly toast coriander, cumin, and fennel until fragrant. Remove spices and finely grind using a spice or coffee grinder.
In a large bowl, combine wet paste, dry spices, sugar, salt, remaining oil, and chicken and mix. Cover and marinate in the refrigerator at least 4 hours.
Soak bamboo skewers in cold water for 15 minutes. Slide 3 or 4 pieces of chicken onto each one, leaving half the length of the skewer empty.
Make a glaze by combining remaining marinade with 1 cup water in a small saucepan and bringing to boil for about 6 minutes.
Prepare grill for high heat and grill batches of skewers for about 8 minutes, flipping every 2 minutes. After 8 minutes, brush glaze onto both sides of each skewer, then grill for an additional 2 minutes on each side, until the glaze caramelizes into a golden crust.