I was playing with friend.
I have discovered that two players cannot roast steaks on sticks at the same time on same bonfire placed in fireplace inside house.
I was not able to roast when he was roasting, but when he finished roasting I was able to roast. When I started roasting he was not able to roast.
When you try it action circle appears, but will disappear almost instantly.
(We were in elevated green house in Vybor - first house from east (map Chernarus).