Merchants brought Samosa from middle-east about 600 years ago
Portuguese brought Potato to India about 350 years ago
And soon they got married forever.
Till then Samosa was filled with meat only.
So if Samosa is not Indian by Origin,
Samosa with Aloo that we know today is purely Indian.
(thanks to https://www.facebook.com/gopalthakkarfoodaddictsindia for correction)