You have established in various comments that the intended meaning is
To get the green sauce, chop the herbs.
This is obviously an imperative construction. In German, this would usually be rendered in one of the two following ways:
- an unpersonal infinitive
- using the formal Sie-form of the imperative
In the context of a recipe, the former is more likely, if you are telling someone verbally e.g. in a cooking course I would expect the latter. In any case, here are the two typical ways:
Um die Grüne Soße zu erhalten, die Kräuter hacken.
(Corresponds to your suggestion 2)
Um die Grüne Soße zu erhalten, hacken Sie die Kräuter.
(Similar to your suggestion 1 but including the pronoun Sie.)
Thus, for the intended meaning only 2 is correct (but 1 is close).
Sentence 1 in the way you present it can indeed be understood in a grammatically sound way. This is because of German’s liberal word order and in this case the ambiguity of case. Note that in the intended example, die Kräuter must be accusative because they are on the receiving end of the action. However, accusative and nominative are indistinguishable in the plural and assuming die Kräuter to be nominative would create another almost allowed sentence.
Um die Grüne Soße zu erhalten, hacken die Kräuter.
The meaning here is that the herbs are cutting/hacking something so that they (the herbs) may receive the green sauce. The only unanswered question is what they are hacking but if sufficient context was established previously it could be said or written that way.
Note that nobody would ever confuse this for a cookbook entry; in speech due to the emphasis being placed differently, in writing because it is ‘too wrong’.