Preheat your oven to 300°F (150°C).
In a small bowl, combine the smoked paprika, garlic powder, onion powder, sea salt, and black pepper to create a dry rub.
Apply the spice rub evenly over all sides of the beef brisket, pressing it into the meat to ensure it adheres.
Place the seasoned brisket in a roasting pan, cover tightly with heavy-duty aluminum foil, and roast for 3 to 4 hours until the meat is tender.
While the beef is resting after roasting, heat the olive oil in a skillet over medium-low heat.
Thinly slice the yellow onion and add it to the skillet, sautéing for 20 to 25 minutes while stirring occasionally until the onions are golden and sweet.
Steam the green beans for approximately 5 minutes until they are vibrant and tender-crisp.
Slice the rested brisket against the grain and serve topped with the caramelized onions and a side of green beans.