Cosmic Fire Ritual
The Cosmic Fire is the ritual fire of the Good Order of the world. It is presided over by Mithras. The aim of the Cosmic Ritual is to symbolically represent the work we need to do to maintain and strengthen Asha in the world.
We can use the traditional Zoroastrian fire temple rituals as an inspiration for our own Mithraic rituals. If so then rituals should ideally be performed by a team of eight people in rituals which have seven roles with the eighth person being the conductor of the ritual. Where less than eight people are present then some people can take on more than one role. In the traditional ritual a major theme is the maintenance of purity. Traditionally also only male priests preside at these rituals, though Mithraists do not have to keep to this. The seven roles could perhaps be named after the seven members of the heptayazata.
Domestic Fire Ritual
The Domestic Fire is the ritual fire of home and community. Rituals around the fire represent the work needed to keep the family and community healthy, strong, harmonious and protected. Continuous feeding of the fire with good quality materials is an important part of this.
The goddess Anahita presides over the ritual, though it is Hestia who is most associated with the work of tending the fire. Maybe we can get inspiration for this ritual from the records of Greek and Roman practices associated with the hearth fire goddesses Hestia and Vesta.
There is scope for other rituals and forms of worship. These could take inspiration from rituals performed by historic polytheists or modern neopagan groups.