Rendering 'Nduja

Nduja is a soft, spreadable Calabrian salami that doubles as a built-in sauce fat. Rather than stirring it in at the end, render it first: warm it gently with your aromatics until the lump melts into a rust-red, oily paste and its fat runs free. That released fat is what carries the flavour through the sauce and gives you something to emulsify with — the move that takes a sauce from sitting on the pasta to actually dressing it. Buy a soft, spreadable 'nduja, not a firm cured one, and keep the heat gentle so the fat renders rather than scorches.