Set your grill to medium heat, approximately 350°F (175°C). Close the lid and allow it to preheat while preparing the potatoes.

Wash the potatoes thoroughly to remove any residual dirt. Using a fork, pierce each potato several times to allow steam to escape during cooking.

Place the potatoes in a large mixing bowl and drizzle with the olive (or avocado) oil. Using your hands or a brush, ensure each potato is evenly coated. In a separate small bowl, add enough coarse sea salt to coat the potatoes. Roll each oiled potato in the salt until the skins are lightly and evenly covered.

Arrange the salted potatoes on a microwave-safe dish. Cook on high power for 4 to 6 minutes. This step helps initiate the internal cooking process, reducing total grilling time.

Wrap each potato tightly in aluminum foil. Place the wrapped potatoes directly onto the preheated grill grates. Close the lid and cook for 30 to 40 minutes, minimizing the number of times the lid is opened.

After 30 minutes, carefully unwrap one potato and pierce it with a fork. If the fork inserts easily into the center, the potato is fully cooked. If resistance is felt, continue grilling for an additional 5 to 10 minutes.

Remove all potatoes from the grill. Discard the foil and slice each potato lengthwise. Fluff the interior with a fork and serve immediately with preferred toppings such as butter, sour cream, cheese, or chives.