Hot dog with bratwurst and kale

Ingredients:

• 8 bratwurst sausages
• 8 hot dog buns
• 2 tablespoons of vegetable oil
• 350 g red onion, cut into 0.5 cm rings.
• 3 tbsp (45 g) butter at room temperature
• 150 g of kale
• Hot brown or Dijon mustard for filing

Preparation:

1. Preheat the oven to 100°C. Heat the oil in an electric skillet on low heat. Add the onion and season with salt and pepper.
   
   Place the sausages around the onions and cook until the onions are lightly browned on the bottom, 3-4 minutes. Flip the onion rings (don't worry if they fall apart), season with salt and pepper, and cook until the onions are browned and slightly crisp on the other side, 4 minutes. Transfer the onions to a medium bowl and set aside.
2. Keep an eye on the sausages while you cook the onions, turning them frequently, until they are deep brown on all sides and a meat thermometer inserted into the center reads 160°F (70°C), about 20 minutes.
   
   Transfer the sausages to a small rimmed baking sheet and keep warm in the oven. While they're frying, brush the insides of the buns with butter.
3. Place the cabbage in the pan and turn it once or twice with tongs to coat it in the sausage fat. Season lightly with salt and continue turning until the cabbage is tender, about 2 minutes. Transfer to the bowl with the onions.
4. Wipe the pan dry with a paper towel. Place the buns, buttered side down, and toast until golden brown, about 2 minutes. Before serving, spread the buns with mustard, top with a sausage, and garnish with cabbage and onions.