Soak bamboo skewers in water about 30 minutes. In a bowl, combine chicken, 2 tbsp olive oil, rosemary and salt and pepper.
Toss to coat. Heat an indoor grill pan to medium-high, and coat with 1 tbsp olive oil. (You can also use an outdoor grill.)
Thread chicken pieces onto skewers. Cook skewers on grill pan or grill, turning occasionally, until cooked through, about 15 minutes. In a bowl, stir together yogurt, juice, mint and remaining 1 tsp olive oil.
Top chicken skewers with yogurt-mint sauce. Garnish with fresh mint, if desired, and serve with brown rice, if desired.