In a delightful article about offerings at Carrawburgh,
There are a few things that I wish had known before creating my mithraeum, but the good news is, I knew of the pines cones and found them utterly charming. While shopping before the event, the wife and I were in the parking lot of a shopping center, eyeing some nearby pine trees. She’s just so sweet and supportive, as she hopped out of the car and began collecting fallen cones.
So when I built a mithraeum in my hotel room, I brought along two kinds of offerings: pine cones and bull’s blood wine.
Back at home, things are decidedly different. First and foremost, I can burn incense. No need to worry about setting off smoke alarms, or paying for clean up of a non-smoking room. I have a plastic shoe box of stick incense and typically I’m “told” what to burn. Mithras seems to favor sandalwood, FYI.
I can also light candles at home. At the Marriot I used battery operated candles, again, so as not to set off any alarms. When I enter my studio at home, typically my first thing to do is lit the candle before Nemesis, and the one on the main, Mithras altar. These burn as long as I’m in the room.
On the other two altars are various offerings that change as I want. Barley, pine cones, wine, flame (in the form of sterno), etc. I have two Roman-like glasses I use for wine, and recently purchased a patera so I can actually pour libations. That’s right! Don’t mess with me!
In the voice-over, diorama/reconstruction of the mithraeum at Carrawburgh in the (then) New Castle upon Tyne Museum (now the Great North Museum: Hancock) there is a cockerel spilling over the top of the far right altar. I’m going to guess that such bones were found on site and prompted the bird’s inclusion.