The Abbey of Santa Maria di Grottaferata was originally founded in 1024 by John XIX, so it predates the schism. Most of the original structures are gone.

As you can see, the inside of the church is very Romanesque –

But there is a nice Iconostasis – note the presence of the choir stalls

A closer look at the Icon of the Blessed Mother – Byzantine and Baroque/Rococo:

This is the baptismal font:

One of the original mosaics:

The millennial icon of the Blessed Mother for the monastery:

You can find out more about the monastery at its web site.