How would you say the following sentence in spanish using the impersonal se? "one eats very well in mexico."

Uno come muy bien en Mexico.

Impersonal sentences in Spanish lack of a grammatical subject, this means there is not an explicit subject (there is no tacit subject).

In other words: no element present in the sentence (explicit) plays the role of subject.

In this type of sentences, the verb must always be conjugated in the third person of the singular, preceded by the pronoun or particle se. As shown below:

Se + verb conjugated with the 3rd person singular + complement

For example, in the following sentence:

Se come muy bien en México

The verb comer (to eat) is conjugated in present (indicative) with the 3rd person in singular he/she/it, as come (eats) .