Pat the chuck roast dry on all sides with paper towels. Season the entire roast generously with salt, black pepper, Kinder’s Salt, Pepper & Garlic Seasoning and smoked paprika. Press the seasonings into the meat so they adhere.
Heat the oil in a large braiser, Dutch oven or heavy-bottomed skillet over medium-high heat. When the oil is hot and shimmering, carefully add the roast. Sear without moving it for 7-10 mins per side, or until a deep brown crust forms. Turn and repeat on every side, including the edges. Transfer the roast to the Instant Pot. Cut roast into 4 pieces to fit nicely into the instant pot.
Reduce the heat under the braiser to medium. Add the onion, leek, carrots and celery to the same pan. Cook, stirring occasionally, for 4 to 5 minutes, until the vegetables begin to soften and pick up some of the browned bits from the bottom of the pan.
Add the tomato paste and stir it into the vegetables. Cook for 1 to 2 minutes, stirring frequently, until the tomato paste darkens slightly. Add the garlic and cook for about 30 seconds, just until fragrant.
Sprinkle the flour evenly over the vegetables. Stir well so the flour coats the vegetables and cook for 1 minute. This cooks out the raw flour taste and will help thicken the gravy later.
Slowly pour in about 1 cup of the beef broth while stirring. Use a wooden spoon to scrape the bottom of the pan to loosen all of the browned bits left behind from searing the roast. These browned bits add lots of flavor to the gravy.
Carefully pour the vegetables and liquid from the braiser into the Instant Pot with the roast. Add the remaining beef broth, Better Than Bouillon Beef Base, Worcestershire sauce and soy sauce. Stir the liquid around the roast until the beef base dissolves. Add the fresh herb bouquet and the butter, if using. The roast does not need to be completely covered with liquid.
Secure the lid on the Instant Pot and make sure the steam-release valve is set to **Sealing**. Select **Pressure Cook/Manual** and cook on **High Pressure for 1 hour and 15 minutes**. The Instant Pot will take approximately 15 to 20 minutes to come to pressure before the 1-hour-and-15-minute cooking timer begins.
When the cooking time is complete, do not immediately open the steam-release valve. Allow the Instant Pot to **naturally release for 20 to 30 minutes**. Once the pressure indicator has dropped, carefully open the lid away from your face.
Carefully lift the roast from the Instant Pot and transfer it to a large platter or cutting board. The meat should be very tender and pull apart easily with a fork. Loosely cover it with foil while you prepare the gravy.
Pour the cooking liquid through a fine-mesh strainer set over a large bowl or saucepan. Press gently on the vegetables to release some of their liquid, then discard the cooked vegetables and herb stems. For an extra-smooth gravy, avoid pressing the vegetables too firmly through the strainer.
Pour the strained cooking liquid into a saucepan or back into the braiser. Bring to a gentle boil over medium-high heat, then reduce the heat to maintain a steady simmer. Cook for **10 to 15 minutes**, stirring occasionally, until the gravy has reduced and thickened to your liking. Keep in mind that the gravy will thicken slightly as it cools. You can add 1 tbsp cornstarch to thicken the gravy and finish with 1 tbsp butter.
Taste the gravy before adding any additional salt. The Better Than Bouillon, soy sauce, Worcestershire sauce and seasonings all contain salt, and their flavors become more concentrated as the gravy reduces. Add salt and black pepper only if needed.
Break the pot roast into large, tender pieces and serve over creamy mashed potatoes. Spoon plenty of the hot gravy over the roast and potatoes and finish with freshly chopped parsley.