1. Drizzle oil into a 5½-quart dutch oven and heat over medium heat. Add lardons and sauté until just browning on the edges, 3 to 4 minutes. Add the shallots and garlic and cook, stirring occasionally, until softened, another minute. Add the vermouth or white wine and bring to a boil. Add the chicken stock and then the mirin.
2. Whisk in the dwengjang and gochujang until dissolved. Stir in the red chilies and then the mussels.
3. Cover and shake occasionally to mix. Cook about 3 minutes until the shells are all open.
4. Discard any mussels that don’t open.
5. Serve in large bowls to share and scatter chopped chives on top to garnish. Serve with rice on the side.