Slice the potatoes. I quartered mine.
Place in a pot of water, and bring to a boil.
Add 1/2 tsp salt.
Reduce heat, and cook until tender, about 12 minutes.
Drain and cool.
Place the potatoes on the grill, cut-side down and grill until lightly golden brown.
Turn the potatoes over and continue grilling until just cooked through.
While the potatoes are cooking, make the dressing by mixing the red wine vinegar, 1/4 cup water, olive oil, garlic powder, oregano, basil, salt, and pepper.
Remove the potatoes from the grill and immediately stir in with dressing and green onions.
Serve once cooled to room temperature.