In a food processor or high-speed blender, blend cashews, lemon, water and salt on high until smooth and creamy.
In a large, airtight container, combine Tandoori paste, cashew 'yoghurt' and sweet potato slices. Pop the lid on and give it a good shake until the marinade covers all the potato.
Place container in fridge overnight.
The next day/night, remove container from fridge and pre-heat oven to 180C.
Lay potato slices on a baking sheet and tray and pour marinade over the top. Bake until potato is soft.
Remove potato from oven, place in a bowl and mash with a fork, and allow to cool.
Allow 3 filo sheets per triangle/parcel and spray oil between each sheet before turning it over onto itself. Fill with a few spoonfuls of potato mixture (depending on how large you want them) and roll up into triangles or parcels.
Place parcels on a clean baking sheet and top each with a spray of oil and a sprinkle of chia seeds.
Bake until golden.
Serve with a fresh, crunchy salad and minty 'yoghurt' dressing.