I would like to make Nigella's Spinach, Avocado and Pumpkin Seed salad but I haven't been able to find pumpkin oil. what could I use as a substitute?
Pumpkin oil (sometimes labelled as pumpkin seed oil) is an oil made from toasted pumpkin seeds. It has a nutty flavour but is quite strong so is often used in small quantities. In Nigella's Spinach, Avocado and Pumpkin Seed Salad (from Feast) it is used in combination with groundnut (peanut) oil which has a more neutral flavour.
You may be able to find the oil in a health food or natural food store. Otherwise you could use an oil with a similar flavour, such as walnut oil or toasted sesame seed oil (Asian sesame oil). Avocado oil doesn't have quite the same flavour but would also work well in this salad, or extra virgin olive oil could also be used.