Preheat oven to 400°F. Pierce the potatoes with a fork. Rub with olive oil, sprinkle with 1 teaspoon sea salt, and place on a baking sheet. Bake for 50–60 minutes, or until the potatoes give slightly when pressed.
Let the potatoes cool slightly (about 10 minutes). Carefully cut the potatoes in half lengthwise (they will be hot). Scoop out the potato pulp from each potato half, leaving about ¼ inch of potato pulp attached to the skin.
Place the potato pulp in a large bowl. Add the sour cream, 1 teaspoon sea salt, and ½ cup of the cheddar. Mash with a potato masher until the potato pulp is relatively smooth. Stir in half of the chives and half of the pimentos.
Place the potato skins in a single layer on a baking sheet. Spoon the potato pulp into each of the potato skins until it meets the top of the potato skin (you may not use all of the pulp). Top with the remaining 1 cup of cheese.
Bake for 15–20 minutes, or until the cheese has melted. Top with the remaining pimentos, remaining chives, and bacon. Serve immediately.
Notes
Russet potatoes are best for making these potato skins. Look for similarly sized, small russet potatoes, either in a bag or sold individually. Make it ahead: prepare the potatoes as directed, but do not bake them. Wrap the sheet pan tightly with plastic wrap and refrigerate for up to 24 hours. Bake for 20–25 minutes, or until warm throughout.