• Assemble all ingredients and equipment before starting.

For Mashed Potatoes:

• Peel the russets and cut into roughly 1-inch pieces. Place in a heavy pot, cover with cold water, season with salt, and bring to a boil. Cook until a fork slides through the potatoes easily, about 10–12 minutes, then drain thoroughly.
• In a small saucepan over low heat, combine the heavy cream, butter, and black pepper. Warm gently until the butter melts and the mixture is heated through—do not boil.
• Return the drained potatoes to the warm pot, add the cubed cream cheese, and press the potatoes through a potato ricer in batches into the pot. Pour the warm cream and butter over the riced potatoes and stir until completely smooth. Add more cream if you prefer a looser texture and season with kosher salt and extra pepper to taste.

For Pot Roast:

• Heat the oven to 325°F (160°C). Pat the roast dry and season all over with the kosher salt and black pepper. Warm the olive oil in a Dutch oven over medium heat until shimmering, then sear the roast 3–4 minutes per side until well-browned. Remove the meat to a plate.
• Add the onion wedges and carrot chunks to the same pot and cook 5–7 minutes, stirring occasionally, until they begin to caramelize. Stir in the garlic and tomato paste and cook another 1–2 minutes to develop flavor.
• Pour in the beef broth and add the Worcestershire sauce, scraping up any browned bits from the pan. Nestle the roast back into the pot and add the thyme sprigs and bay leaves. The liquid should reach roughly halfway up the sides of the meat; add extra broth if needed.
• Cover with a tight-fitting lid and transfer the pot to the preheated oven. Bake for 2 hours, then test the roast with a fork—if it doesn’t fall apart easily, continue cooking and check every 20–25 minutes until the meat shreds with little resistance (a 2½-pound roast can take closer to 3 hours).
• When the roast is fork-tender, remove the meat to a clean plate. Stir the Dijon mustard into the pan juices and use an immersion blender to puree the cooking liquid and softened vegetables until silky. If the gravy is too thick, thin with additional beef broth. Shred the beef, return to the pot if desired to warm, and serve alongside the mashed potatoes with plenty of gravy.