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.
Coat the beef brisket evenly with the spice rub, pressing it firmly into the meat.
Heat the olive oil in a heavy, oven-safe skillet or Dutch oven over medium-high heat and sear the brisket for 3-4 minutes per side until a dark crust forms.
Remove the brisket temporarily and add the thinly sliced yellow onions to the pan, sautéing for 5 minutes until they begin to soften and brown.
Pour in the beef bone broth to deglaze the pan, scraping up any flavorful browned bits from the bottom.
Place the brisket back into the pan on top of the onions, cover tightly with a lid or double layer of foil, and roast in the oven for 3 to 3.5 hours until the meat is fork-tender.
During the last 10 minutes of roasting, steam the green beans until vibrant and tender-crisp.
Allow the brisket to rest for 10 minutes before slicing against the grain and serving with the jammy caramelized onions and steamed beans.