Liguria — inland Liguria, winter alternative to basil pesto
An alternative pesto tradition from inland Liguria using wild rocket (rucola selvatica — more bitter and peppery than cultivated) combined with walnuts rather than pine nuts, garlic, Pecorino Sardo, and Ligurian olive oil. The wild rocket is not blanched — it is used raw, producing a more bitter, more peppery pesto than the basil version. Walnuts replace pine nuts as the fat component. This pesto is darker in colour (deep green-brown from the rucola), more assertive in flavour, and pairs particularly well with trofie or trenette. A winter pesto when basil is not available.
Bitter, peppery, walnut-rich; the rucola selvatica's isothiocyanates provide a mustard-like heat; Pecorino Sardo's sharpness echoes the rocket's aggressive character; this pesto is not for the mild-palated — it is for the lover of bitter, peppery food
{"Use only wild rocket — cultivated rocket is too mild; the bitterness and peppery heat of wild rocket are what distinguish this from a mild green pesto","Walnuts should be freshly shelled — oxidised walnut halves have a bitter, rancid note that makes the pesto harsh rather than pleasantly bitter","Mortar and pestle preferred — the cell-rupture method releases wild rocket's volatile oils differently from a food processor's blade","No blanching the rocket — it is the raw bitterness and peppery compound (isothiocyanates) that define this pesto; cooking removes them","Pecorino Sardo rather than Parmigiano — the sheep's milk cheese's salt and sharpness is the appropriate counterpoint to the rocket's bitterness"}
{"A small amount of Ligurian olive oil (lighter than Tuscan) added last preserves the pesto's fresh colour","If wild rocket is unavailable, a 50:50 mixture of cultivated rocket and fresh watercress approaches the bitterness level","The pesto can be thinned with pasta cooking water at service — rocket pesto thickens as it sits","This pesto is excellent on bruschetta with fresh ricotta and a few walnut halves as a starter"}
{"Cultivated rocket — too mild; the wild variety is essential for the correct bitterness level","Old walnuts — rancidity is the most common failure; use fresh-season walnuts only","Food processor at high speed — the heat and blade action bruises the wild rocket differently than the mortar; the colour goes from green-brown to grey","Too much garlic — wild rocket and garlic are both pungent; one small clove is sufficient"}
La Vera Cucina Genovese (Emanuele Rossi)