Vegan Sausage Rolls with sage and red onion

Peel and finely chop the red onion.
Heat the oil in a frying pan and gently fry the onion for 3-4 minutes. Finely chop the sage leaves, stir through the onion and set aside.
Slit the sausage skins and peel them off the sausages and discard. Put the sausage 'meat' into a bowl and mash with a fork.
Add the onion and sage to the sausage meat, then grate in the cheese. Mash everything together.
Unroll the puff pastry. Divide the sausage mixture into three equal parts and lay it in long strips on the pastry.
Slice the pastry lengthways between each sausage section as pictured....
... then brush the pastry edges with a little water.
Roll up the pastry to completely cover the sausage filling, sealing the edges well. Roll back and forth on the work surface to create a round cylinder.
Trim the edges from the pastry, then cut each cylinder into four equal parts. Lay these on an oiled baking tray.
Mix the dairy-free milk with a few drops of soy sauce (optional) and brush over each sausage roll.
Finally, sprinkle them with poppy seeds.
Chill the rolls for about 30 minutes in the fridge. Meanwhile, preheat the oven to 180ºC (fan) / 350ºF / Gas Mark 4. Bake for 20-25 minutes until golden and crispy.