I'm allergic to pine nuts, is there another nut I can use to make pesto?
It's not even necessarily a substitution, as pesto is just a type of sauce made from a pounding up herbs and other stuff in a mortar & pestle.
It's just that most pesto that people see is the traditional 'basil pesto' aka 'pesto Genovese' which is garlic, oil, salt, basil and pine nuts, so they assume that it's the only 'pesto' ... you can find plenty of recipes searching for:
- Pesto Sicilian
- Pesto Trapanese
- Pesto Rosso
- Pesto Pantesco
- Pesto Calabrese
In terms of nuts, I've seen recipes calling for hazelnuts, almonds, pistachios, pine nuts, walnuts, or even a combination of multiple nuts. I'm guessing they'd use whatever is abundant and in season in that particular region.
I've seen anchovies, capers or olives in place of straight salt; plenty of types of herbs, or even greens like spinach or arugula (aka rocket for the Brits).
(And on Good Eats, Alton Brown was a fan of pistachios in pesto; if I recall correctly, part of the argument was they were already green.)
Pine nuts are not actually nuts. They are seeds found inside the structure of the pine cone. Technically, sunflower seeds would provide the most similar flavor when looking for a pine nut substitution in traditional recipes. Sesame seeds would also offer a solution to those with nut allergies that don't have pine nuts on hand.