For the sausage wreath, first preheat the oven to 200 °C hot air. Line a baking tray with baking paper.
Cut the puff pastry into strips widthwise and cut these strips in half. The strips should be wide enough to cover a good portion of the sausages. Cut the strips in half.
Wrap each of the Bern sausages with a puff pastry strip. Place the sausages in a wreath shape on the baking sheet. The puff pastries should touch each other so that the wreath will hold together later.
Cut a lengthwise strip from the leftover puff pastry. Twist the strip in around itself and then form it into a mesh. Place this on top of the wreath.
Whisk egg with milk and salt. Brush the puff pastry with it.
Put the sausage wreath in the oven and bake until the puff pastry is done (takes about 15 minutes).
Here you can find the video for the recipe.