Preheat oven to 400° F and line a baking sheet with parchment paper.
Scrub potatoes and dry thoroughly. Pierce all sides of each potato with a fork.
Bake potatoes directly on middle oven rack for 35-45 minutes, or until easily pierced through the middle with a knife. (*Baking time will depend on the size of your potatoes. Mine took 35 minutes.)
Allow the potatoes to cool on a wire rack for about 15 minutes, or until cool enough to handle.
Preheat broiler to 500° F or high.
Cut each potato in half and scoop out the middle, leaving a bit of potato in each skin. Save the potato fillings to use in another dish.
Using a basting brush, brush both sides of the potatoes with melted butter and sprinkle generously with sea salt.
Place potatoes skin side up on prepared baking sheet on the middle oven rack. Broil for 6-7 minutes or until butter starts to bubble and skins become crispy. Be sure to keep an eye on them so they don’t burn!
Fill each potato skin with a small spoonful of taco meat and top with a sprinkle of shredded cheese. Broil another 4-5 minutes, or until cheese is melted and beginning to turn golden brown.
Top each potato with a few black olives, tomatoes, and green onions. Dollop with sour cream and salsa if desired.