Cut the chicken into 1/2-by-4-inch strips; you shoulod have about 30 strips. Refrigerate in a large bowl until needed.
To make rub: Heat 3 tablespoons of the oil in a small nonstick skillet or saute pan over medium heat. Cook teh onion, uncovered, stirring ocasionally, for 4 to 5 minutes, or until deep brown. Do not let the onion scorch. Add the garlic and cumin and mustard seeds and saute for 30 seconds. Do not brown the garlic.
Remove from the heat and mix in the lime juice, jalapeno, fresh herbs, salt, and pepper. Transfer the mixutre to a food processor (a small one is best) and , with the machine running, drizzle in the remaining 3 tablespoons oil and the water and process to a paste-like consistency.
Add the rub to the chicken strips adn mix well. Marinated, refrigerated, for at least 4 hours or preferable overnight.
Meanwhile, to make the spiced yogurt dip: Mix all the dip ingredients together in a small bowl until smooth. Refrigerate until ready to serve.
When ready to cook the chicken, soak the bamboo skewers in water for at least 1 hour. Prepare a medium-hot fire in a charcoal grill, or preheat a gas gril to medium-high. "Oil the grill. Threade the chicken on the skewers. Grill for about 2 to 3 minutes per side, or until cooked through.
Serve the skewers on a platter, with the yogurt dip in a small bowl in the center for guests to help themselves. Garnish with cilantro sprigs adn lime weges for squeezing.
TIP: You can also bake the chicken. Preheat and oven to 475 degress f. Spray 2 baking sheets with cooking spray or lightly oil them. Place the skewers, spaced apart, on the baking sheets, and bake for 8 to 10 mminutes, or until cooked through.