Marie Curie (Sausage Sandwich)

Preparation

1. In a bowl, mix the salt and water to make a brine. Thinly shred the red cabbage and add it to the brine along with the fennel seed. Pour the mixture into a vacuum pouch or Ziploc bag and seal. Then let it cure for two days under refrigeration.
2. Prepare the ketchup. Place all the ketchup ingredients in a blender or food processor and blend until smooth. Taste, and adjust the seasoning to your liking. Store in a squeeze bottle.
3. In a medium saucepan bring 2 liters (8 cups) of slightly salted water to a boil. Wash the potatoes well and cut into wedges. Poach the potatoes in the boiling salted water for 7 minutes, and then remove from the water. Drain and dry on a paper towel. In another medium saucepan, heat the oil to 180°C (360°F), and fry the potatoes until they brown. When they are done, remove them from the oil, and place in a colander lined with absorbent paper.  Set aside.
4. Lightly grease the sausages. Heat a skillet or grill to medium, and cook the sausages for 5 minutes. When the sausages are ready, slice the croissant lengthwise and spread a small amount of the ketchup on the bottom half. Place the sausages on the prepared croissant base and top with some pickled cabbage.  Place the potato wedges on top of the sausages and cabbage. Spread more ketchup between and on top of the potato wedges. Top with the other croissant half, and serve.