My aunt brought this over last week, and I couldn’t believe it’s just 4 ingredients

If you have picky eaters, you can skip the mushrooms in a few of the rolls and just fill those with Swiss cheese, then mark them with a toothpick so you know which is which. For a milder flavor, use baby Swiss or even provolone instead of regular Swiss. If your steak slices are very thin and delicate, you can secure the rolls with toothpicks before baking; just remember to remove them before serving. To stretch the meal for a bigger family, slice the finished rolls into medallions and fan them out over mashed potatoes or noodles, then spoon the gravy over the top. For a slightly lighter version, use one can of gravy and serve the rolls over buttered noodles so the noodles help catch the extra juices. You can also make this ahead: assemble the rolls and pour on the gravy, cover, and refrigerate up to 24 hours, then bake a little longer straight from the fridge until everything is hot and tender.