Step 1: Preheat your oven to 400°F (200°C).
Step 2: Scrub the 4 large russet potatoes thoroughly under running water, then pat them completely dry. Use a fork to poke several holes all over each potato to allow steam to escape during baking.
Step 3: Rub each potato all over with 1½ tablespoons of olive oil, then sprinkle generously with salt and a little black pepper. Place the potatoes directly on the oven rack (you can place a sheet pan on the rack below to catch any drips for easier cleanup).
Step 4: Bake for 45 to 60 minutes, or until a skewer or fork slides in easily without resistance, indicating a soft, fluffy interior. The skin should be crisp.
Step 5: While the potatoes bake, cut 1 pound of steak (sirloin, ribeye, or flank) into uniform, bite-sized pieces. Pat the steak pieces dry with paper towels; this is crucial for achieving a good sear rather than steaming them.
Step 6: In a medium bowl, toss the steak pieces with salt, pepper, 1 teaspoon garlic powder, and 1 teaspoon paprika. Ensure all pieces are evenly coated.
Step 7: When the potatoes have about 10 to 15 minutes remaining in their baking time, heat 1 tablespoon of butter in a large skillet over medium-high heat. Once the butter is foaming and fragrant, add the seasoned steak pieces in a single layer. Work in batches if necessary to avoid overcrowding the pan, which can lower the temperature and prevent proper searing.
Step 8: Sear each side of the steak for approximately 2 minutes (about 4 minutes total), until a beautiful brown crust forms and the interior reaches your desired doneness (e.g., 125°F for medium-rare, 135°F for medium).
Step 9: Transfer the seared steak to a plate and cover loosely with foil to rest. This allows the juices to redistribute, keeping the meat incredibly juicy and tender.
Step 10: Remove the perfectly baked russets from the oven and let them rest for 5 minutes. Using a sharp knife, carefully cut a lengthwise slit in the top of each potato. Gently squeeze the ends of the potato to open it up, creating a well for your toppings.
Step 11: Fluff the interior of each potato with a fork to create a light, airy bed for the toppings and to help melt the cheese.
Step 12: Sprinkle about ¼ cup of shredded cheddar cheese into each opened potato. Return the potatoes to the oven—or, for faster melting and a slightly crisper top, place them under a preheated broiler—for 1 to 2 minutes, just until the cheese is melted and begins to bubble. Keep a close eye on them under the broiler to prevent burning.
Step 13: Arrange a generous handful of the seasoned, seared steak pieces atop each cheesy potato. The residual heat from the potato and melted cheese will gently warm the steak through, merging all the wonderful flavors.
Step 14: Dollop 2 tablespoons of sour cream onto each potato, then sprinkle with 1 tablespoon of freshly chopped green onions.
Step 15: For extra flavor, texture, and visual appeal, scatter 2 to 3 tablespoons of optional toppings like cooked broccoli florets, savory sautéed mushrooms, or zesty pickled jalapeños over the top.
Step 16: Transfer the loaded potatoes to plates or a serving platter. Serve them hot and encourage everyone to stir the toppings into the fluffy potato interior for each customized, delicious bite!