In a saucepan, cover potatoes with water.
Cook over medium-high heat until tender; drain.
Let potatoes cool; cut in half and place in a large bowl.
Drizzle with the olive oil and toss well.
Place potatoes in a grill basket; season with salt and pepper.
Place basket on grate over medium-high heat.
Cook for 5 minutes; stir well and cook another 5 minutes, or until golden.
Remove potatoes to a bowl; toss with butter and remaining ingredients.
Serve warm.