In a large flameproof cast-iron casserole, heat the 2 tablespoons of oil. Add the onion and garlic and cook over moderate heat until softened. Stir in the andouille and beef jerky. Add 2 1/2 cups of the broth, the bay leaf and oregano and bring to a boil. Cook for 10 minutes, stirring frequently. Add the beans and their liquid and simmer for 15 minutes longer. Discard the bay leaf.
Meanwhile, light a grill. Mound the rice on the bottom half of a large sheet of nonstick heavy-duty foil. Fold the foil over the rice; fold up 2 of the sides and crimp. Pour the remaining 2 tablespoons of broth into the rice packet and crimp the remaining side. Set the packet on the grill and heat the rice until warm.
Brush the plantains with oil and grill over moderately high heat, turning once or twice, until lightly charred and tender, about 5 minutes. Carefully open the rice packet and serve with the feijoada and plantains.