It is 30 to 50% blood, along with chopped-up meat from the pig’s head, tongue, lungs, heart and pork rind. Bread is often added. Instead of being put into a casing, it may be put into a pot, tinned, or it may be dried.
It is served sliced thickly. The taste of the slices is often complimented by a splash of wine vinegar.
In Aveyron, it is often served with onion.
It can also be baked in flaky pastry (as in “Mini Pithiviers de pommes au boudin noir.”)