In our parish, a large host is used for Adoration (the kind that is sometimes used at mass and can be broken in several smaller pieces). A triangular block of wood is placed atop our box-shaped tabernacle on a side alter. The top angle of the piece of wood has a small slit cut into it about 1/2" deep. Each week, the parish secretary places the Host in this slit where it is almost completely exposed to the open air. The Host is not always well-centered and gives the appearance it is about to fall.
Is a monstrance required for exposition of the Eucharist? Every resource I’ve checked regarding rules for Eucharistic Adoration assume a monstrance is being used and never state if it is a must.