A Buddy Burner is a cooking appliance made up from using two tins, some cardboard and melted wax.
The heat is gained by covering up and open flame with a can that in height is approximately a third bigger than the small tin can which is housing the wick. The size above the 'wick' tins top is important as the air circulation is needed to keep the flame alight. Suffocation of the flame on the wick causes a smoky mess [or that does not cook the food as the flame struggles to keep alight.
Be warned that while in use and immediately after All the cans get extremely hot. A Buddy Burner is not something that is used in a drought or on high fire danger days.
However when there is cooking needed to be done on a trip that has a lot of rain and inclement weather about as long as the 'wick' does not get overly wet using the buddy burner is a good idea. The cooking surface is the top of the upturned larger can or as in this photo a biscuit tin lid.
A third can, saucepan etc may be added to the top of the upside cooking surface down can. Although experience has shown that the surface can should have both top and bottom ends removed [leaving a cylinder] and then have a pot surface to cook directly on top of the openings.
Another method involves placing thin steel bars through the tin can. Then placing a billy on top of these bars. However the soot on the side of the cooking 'pot' may be hard to get off unless you have soaped the cooking container.
What recipes are able to be used on the buddy burner are varied. All it takes is practice and patience.