Preheat the oven to 400°F (200°C).

Wash potatoes and scrub well, making sure there is no dirt or grit on them. Pat dry with a paper towel. Pierce potatoes with knife or fork a few times to release steam as they bake.

Rub potatoes with olive oil.

Spread a layer of coarse sea salt on the bottom of a large baking dish.

Arrange the potatoes on top of the salt in a single layer.

Sprinkle more salt over the potatoes until they are completely covered with a layer of salt.

Bake the potatoes for 30-40 minutes, or until they are tender when pierced with a knife.

While potatoes are baking, mix herbs into butter with a spoon in a small bowl.

Remove the baking dish from the oven and let the potatoes cool for a few minutes.

Cut a slit down the middle of the potatoes and add herbed butter to the middle. Let melt and absorb.

Use a slotted spoon or tongs to gently remove the potatoes from the salt crust, brushing off any excess salt.

Serve the potatoes hot, optionally drizzled with olive oil and optionally topped with more butter or sour cream.