Answer:
Mexican food, in my opinion, is the most flavorful.
Step-by-step explanation:
The first sentence Mexican food, in my opinion, is the most flavorful is correct in it's use of the commas. The sentence can well stay independent even without the clause (in my opinion). But, with the addition of this phrase, it gives further description and meaning to the subject that is being talked about. This use of the dependent clause to further explain the sentence, also providing personal opinion,makes the sentence much clearer. Also, the use of the commas before and after the dependent clause, gives the correct form of the sentence. Thus, the subject is (Mexican food), clause (in my opinion) and the predicate being (is the most flavorful).