Place the potatoes into a medium pot and cover with water and add kosher salt to season. Bring up to the boil and cook just until al dente. Do not overcook because you are still going to grill them
Drain the potatoes and run them under cold water to cool them down quickly and stop the cooking process. Toss them with the olive oil and check your seasoning. Add salt and pepper if needed.
Meanwhile, while the potatoes cook, clean your ear of corn, chop your green onions, cilantro and halve your lemons. Turn your grill on and heat to medium-high heat.; Grill the corn until heated through and you have nice grill marks. Grill the potatoes until cooked through and you have crispy grill marks on them.
Grill the lemons, flesh side down until you have good grill marks and the juices have heated up. Pull everything off of the grill and cut the corn off the cob.
Toss everything together in a bowl and squeeze the grilled lemon juice over the top and toss again. Serve immediately or at room temperature.
