For the dough, mix 500 g of flour, 2 teaspoons of salt, 1 sachet of instant baker's yeast, 150 g of water, 150 g of milk and 40 g of butter, and knead until the dough is smooth. Rest and leave to rise for 20 minutes. Take small pieces of dough, roll them by hand into a sausage shape and plait them. Plunge them for 3 seconds into a salt bath (1 L of water, 2 teaspoons of table salt and 55 g of baking soda). Sprinkle with coarse salt before baking on a tray at 250 °C for 15 to 20 minutes.