There are reflector ovens that only weigh a few ounces that work quite well with a camp fire. I forget the weight of mine, but it is under a pound (14 ounces maybe). A lighter one than mine could be built, but most of them probably weigh closer to 2 pounds. I have used one while canoe camping, but never carried it on a bike. It would go along with me before some of the items that others carry (chairs and such), but still I will most likely never carry it.

Still the reference was probably an error and he is most likely carrying a stove rather than an oven.