I will introduce a variant of log Gromov--Witten invariants called "punctured invariants" developed in joint work with Abramovich, Chen and Siebert. I will then explain how to use these invariants, in joint work with Siebert, to give a general construction of mirrors by building the coordinate ring of the mirror explicitly in terms of these invariants. The ring is easy to define, but proof of associativity requires delicate issues of gluing stable log maps. This construction can be viewed as a natural generalization of the mirror construction of myself, Hacking and Keel for log Calabi--Yau surfaces.