Put vinegar, 150 g sugar, salt and fish sauce in a pot, bring to the boil and simmer for about 5 minutes. In the meantime peel carrots and radish and cut them into pieces of about 7 cm. Slice or cut the pieces into fine slices, then cut into thin strips.
Put the carrot and radish strips in a bowl, pour the hot vinegar liquid over them and leave to soak for about 30 minutes.
In the meantime peel the garlic and cut it into small pieces. Mix mayonnaise and garlic. Flavour with sugar and chilli. Heat oil in a pan. Fry the sausages for about 8 minutes while turning.
Cut baguette into 4 pieces and halve lengthwise. Place all bread halves on a baking tray and roast in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for 5-8 minutes.
Cut the bratwursts into diagonal pieces. Spread all bread halves with chilli mayonnaise. Take the vegetables out of the brew and let them drip off a little. Spread slices of sausage and pickled vegetables on top. Sprinkle with coriander and place bread lid on top.