Preheat your oven to 400°F (200°C). Scrub the Russet potatoes under cold water to clean them thoroughly, then pierce each potato several times with a fork. Coat the skins lightly with olive oil and sprinkle with salt. Place them directly on the oven rack and bake for about 60 minutes, or until they're fork-tender and the skins are crispy.

While the potatoes bake, heat a large skillet over medium heat and add a splash of olive oil. Sauté finely chopped onion and minced garlic for about 3-4 minutes until aromatic and translucent. Next, add the ground beef to the skillet, cooking until it’s browned, which should take about 5-7 minutes.

Once the beef is browned, incorporate your choice of diced vegetables—like carrots, peas, and corn—and pour in a splash of beef stock. Stir everything together and simmer for about 5-10 minutes until the vegetables are tender and the mixture is well combined.

After your potatoes have finished baking, remove them from the oven and let them cool slightly. Carefully cut each potato in half lengthwise and scoop out the fluffy insides into a large bowl, leaving a thin layer of potato on the skin. Mash the scooped potato with a fork and mix it into the beef filling until well combined.

Preheat your oven to 375°F (190°C). Stuff the potato skins generously with the hearty beef and vegetable filling. If desired, sprinkle cheese on top for that extra creamy touch. Place the filled potatoes back on a baking sheet and bake for an additional 20-25 minutes, until heated through and the tops are golden and crispy.