Soak 7-8 wooden skewers in water, if needed, or use metal ones.

Clean the potatoes and parboil for 4-5 minutes. Transfer potatoes into large bowl and let cool.

Meanwhile, place 2 tablespoons olive oil, minced garlic, rosemary, salt and pepper in a small skillet over medium heat, stirring occasionally. Once garlic begins to turn translucent (~3 minutes), remove pan from heat. Set aside for later.

Preheat grill to high heat.

Once potatoes have been parboiled, slice each one in half. (If potatoes are larger in size, then you may need to quarter them.)

Skewer potatoes and brush with remaining 1 tablespoon of olive oil.

Turn burners on one half of grill off. (If using charcoal, just push lit charcoal to one side of grill.)

Brush grill grates with vegetable oil and place skewered potatoes cut-side down over the lit burners. Grill potatoes for 2-3 minutes, flip and grill for 2-3 more minutes.

Transfer potatoes to the unlit side of the grill. Close cover and allow potatoes to cook for another 5-6 minutes, or until they can be easily pierced with a fork.

Remove potatoes from grill and brush with the garlic and rosemary olive oil mixture. Garnish with fresh chives before serving (optional).