Mix the flour and shredded suet with enough water to form a dough. Roll the dough out quite thinly and then lay the bacon rashers over the dough and sprinkle with onions. Crumble the stock cube and sprinkle it over the top.
Carefully roll up the pastry like you would when making a Swiss roll. Wrap in aluminium foil, making sure to seal very well, and place in a steamer for 2 1/2 hours.