Heat oven to 400F.
Using a large, nonstick skillet, heat 1 tablespoon olive oil over high heat. Add the leeks and saute until softened and fragrant. Remove pan from the stove.
Transfer the leeks to a large mixing bowl. Add the cherries, walnuts, egg, parsley, a couple good pinches each salt and pepper (heavier with the salt), and 1 cup stock. Put the dressing in a casserole dish. Cover tightly with foil.
Put the same large, nonstick skillet back on the stove to heat with the remaining tablespoon olive oil. Add the pork and sear ~1-1/2 minutes per side until seared all over. Transfer the pork to a bake dish and put in the oven to cook. At the same time, put the dressing in the oven to cook as well.
While pork and dressing are cooking, prepare the gravy. Put the skillet with the pan drippings on medium-high heat. Add the flour and stir in, scraping up the browned bits from the pan, to form a roux. Whisk in the remaining 1-1/2 cup stock and heat until thickened. Taste for seasoning and add a bit of chopped parsley if desired.
Let the pork cook ~30-35 minutes or until an inserted thermometer reads 155-160F. Once done, remove the pork from the oven. and transfer to a cutting board to rest 10 minutes. At that time, remove the foil cover from the dressing, and let it cook during this rest time for 10 minutes. During this time, also use a rubber spatula to scrape any additional pan juices from the bake dish into the prepared gravy.
Serve the pork sliced over the dressing, topped with gravy. Yields: 4 servings.