Preheat the oven to 425°F.

Scrub the potatoes under running water and pat them dry. Poke a few holes in them with a fork to allow steam to escape. Coat them in olive oil and sprinkle them with salt. Place the potatoes directly on the oven rack. Place some aluminum foil on the bottom rack directly below the potatoes to catch any oil drips. Bake the potatoes for 60 minutes or until tender. 

When they are tender, remove them from the oven and set aside. 

Heat a large skillet over medium-high heat and add the ground beef. Cook until no longer pink, stirring to break it up as it cooks. Drain the fat. Add the onion and garlic. Cook until the onion is soft and transparent.

Stir in the taco seasoning and water (if you use packaged taco seasoning, adjust the water based on the package directions). Simmer for 8 to 10 minutes until thickened. 

Cut a slit, lengthwise in the potatoes and spread them open.

Spoon a heaping portion of the meat mixture into each potato. Top with cheese, and any other toppings of choice.