In a small bowl combine the salt, pepper, paprika, and garlic powder.
Rub the spice mixture over the chuck shoulder roast to create a thick layer. Let sit while heating the pan.
Heat 2 tablespoons of olive oil or butter in a large cast iron skillet until hot. Test the heat by sprinkling a couple drops of water into the pan. If it sizzles immediately the skillet is ready.
Add the roast into the pan and do not move. Sear it on medium heat for 10 minutes. Repeat for the second side.
After the second side has been seared, flip and pour ¼ cup of the Guinness over the roast. Top with a heavy lid. Cook for 30 minutes on low-medium heat.
After 30 minutes flip the roast, add an additional ¼ cup of Guinness over the roast, cover, and cook for 30 minutes on low-medium heat. Turn the oven to 300 degrees.
After 30 minutes flip the roast, cover, and place into the hot oven.
Every 30 minutes while the roast is in the oven remove it, flip it, and pour a bit of Guinness over the top of the roast to moisten it.
Cook in the oven for a total of 2 hours.
Take out of the oven and let the roast rest for 10-15 minutes before cutting and serving.