Begin by placing a steamer basket into a large pot with about an inch of water and add the potatoes along with the kosher salt. Cover the pot and bring it to a boil over medium heat. Steam the potatoes until they are tender when pierced with a knife, which should take around 25 minutes. Be cautious not to overcook them as they need to hold their shape when flattened. Remove the basket and let the potatoes cool to a manageable temperature.

Once cooled, gently press each potato between your palms to flatten them slightly while keeping them intact (some may break, but that's okay). Heat about 1/4 inch of olive oil in a medium skillet over medium-high heat. Fry the potatoes in batches to prevent overcrowding, cooking each side until crispy and golden brown, approximately 2 to 3 minutes per side. Transfer the fried potatoes to a plate lined with paper towels to drain. Arrange them on a serving dish and sprinkle with sea salt before serving.