Place potatoes in a pot of water and bring to a boil. Cover and reduce heat; simmer for 5 minutes. Drain.
Lightly spray a grill basket with cooking spray. Pour potatoes into pan and grill for about 15 minutes, until cooked through and crisping on the outside.
While potatoes are grilling, whisk together lemon extract, olive oil, salt, and black pepper in a large bowl.
Once potatoes are cooked, pour into bowl and toss to coat evenly with dressing. Add sliced green onions and chopped parsley. Serve immediately or chill until ready to eat.