Place Shiraz in a saucepan and boil-off the alcohol. (A match applied to it will show whether it is all gone...) Then add the stock and the potato and vegetable peelings, which should include the usable parts of the onion peelings. Put in the bayleaves. Separate the sausages, prick them at least three times on each 'side' and place them in the stock. Bring this to a simmer, slowly.
When the sausages are cooked, take them out of the stock and allow them to cool. Strain the stock and discard the peelings, then remove the sausage skins, slice the sausages and sling the slices in the stock. Add the pepper, mace and fenugreek, then bring back to a simmer. Quarter the leeks longitudinally and slice them, adding them to the stock.
Chop the potato, onion, garlic and chilli finely in a food processor (or on a chopping-board) and fry in the olive oil. Slice thinly the bacon and add those pieces and the mushroom slices1 to the fried veg, and continue frying these until everything is cooked.
1 Note that the alkaloids responsible for flavour in most mushrooms is oil-soluble, so mushrooms added to cooked dishes should always be fried, however lightly, first.
Lightly sprinkle plain flour on the fried stuff, stirring with (preferably) a wooden spoon or wooden spatula, and keep doing this until all the excess olive oil is absorbed. While it is still hot add the fried and floured vegetables a little at a time to the sausages and stock without allowing the simmering to stop.
Place the whole in a casserole and continue cooking for about twenty minutes.