In the light of responses from readers, I would like to supplement the following:
1) if the authority prohibits open cooking in public areas by the roadside, in the form of bye-law or not granting any license for such activities then such cooking is not legal, that is, it is wrong in the eyes of the law.
2) if this is not disallowed by law, then whether this is “wrong” could become subjective:
i) whether this is a local commonly accepted practice.
ii) whether those taking the food is adventurous, that is, depending on their risk profile.
However, this can also be viewed from the following perspective:
a) would the environment impact on the hygiene of the food rendering the food unsafe for consumption?
b) would the cooking impact adversely on the environment?
For a) if cooking is carried out in a dirty place, affected by pollutants from vehicles, bacteria from the air and garbage in the vicinity or carried out in an area infested by cockroaches and rodents, then open cooking is “wrong”.
For b) if open cooking causes nuisance to the public, by the gas and noise it emits; the garbage it litters in the public area; the encroachment that denies others the use of the public area (for instance, footpath), or making the area becoming unsightly, then such cooking is “wrong”.
As with everything, there is always a shade of grey, making determination of whether it is “wrong” difficult.. . . . this is where our judgement and wisdom is needed.