Preheat oven to 400F and lightly grease a large sheet pan. Place potatoes on sheet pan and prick several times with a fork.
Bake potatoes at 400F 55-60 minutes until potatoes are tender when pierced with a fork. Remove from oven and cool slightly. Keep oven on.
While potatoes are baking, make the filling. In a large skillet or Dutch oven, melt olive oil and butter over medium heat. Add onions and stir occasionally until onions are a deep caramelized color, about 20 minutes.
Deglaze pan by adding white wine and scraping up any browned bits with a wooden spoon. Add thyme and beef broth and bring to a simmer over medium heat, allowing to cook 3-5 minutes until reduced slightly. Season with salt and pepper to taste.
Once potatoes are cool enough to handle, use a knife to slice potatoes down the middle and use a fork to fluff potato.
Fill potatoes with French onion soup filling and top each potato with shredded cheese. Bake potatoes at 400F 15-20 minutes until filling is bubbly and cheese is melted. Optionally, broil potatoes 2-3 minutes until cheese is browned.
Allow potatoes to cool several minutes before serving warm. Enjoy!