Where does the 'no' come from in tsukuru(no)? Is it a particle or part to tsukuru

Question

So i'm trying to figure this out why you put a の with a 作る(to make)...i.e. mary さんはすしをつくるのがへだです...

Answer 1

の is used to make a noun clause just like こと is.
For this function, の and は are roughly interchangeable.

I think の is more frequently used than こと in daily conversation, because の could be pronouced more easily than the other.

Answer 2

In order to describe a verb or add more sentence onto a verb you have to first turn it into a noun, with either の or こと. So, here the whole phrase すしをつくる acts as one noun when の is attached, and then you just continue as normal. ～がへたです。

Other examples of this same this happening:

本を読むのが好きです　読む　+　の

やったことないです。　（やる）やった　+　こと

そうなんです。　（です・だ）な　+　ん（の）