Inspired by this recent Chef John video.
Prep a whole pork tenderloin as you normally would (I coat with a thin layer of vegetable oil and liberally apply kosher salt). Take a loaf of Italian bread (that's what my local store calls it, it's a long loaf of white bread with sesame seeds on the top), slice in half lengthwise, and coat with butter — I use one stick (1/2 cup) for a whole loaf split in two. Sprinkle on what I consider "stuffing herbs": rosemary, thyme, sage.
Put the tenderloin on top of the buttered side of the bread and press it down a bit to make it stable. Place in a hot oven and roast as you normally would. I put the whole thing on a sheet pan with a rack in it to keep the bread elevated.
When the pork comes out, the bottom side will be a bit pale. Remove the bread and reserve. Put the tenderloin back on the rack, pale side up, and put under a broiler until the top is browned. Remove and let rest before slicing.
While that's happening, roughly chop up the bread, which has absorbed all of the tenderloin cooking juices and is full of butter and herbs, and put in a bowl or baking dish. Add a bit of stock (pork or chicken) to moisten slightly until it looks like dressing. You could serve as is, or put it in a baking dish and pop it under the broiler to crisp up the top a bit.
And as always, enjoy.