[V plain]NVerb clause modifying a noun
Noun modifierA plain-form clause placed before a noun describes it: […が 作った]ケーキ.
これは ミラーさんが 作った ケーキです。
これは ミラーさんが つくった ケーキです。
This is the cake that Mr Miller made.
Japanese has no relative pronoun (“that/which”). The describing clause simply goes in front of the noun, with its verb in plain form. Inside the clause the subject is marked with が (not は).