"The pizza has a lot of oil."
Translation:La pico havas multe da oleo.
This was taken from the "Tips & Notes" of the Food section. Although you can't yet see this on mobile devices, it is available on computers.
"So far we have learned several prepositions, including sur, por, sen, de, da and kun. Note that there is no accusative -n for nouns after prepositions except in specific instances, which will be introduced later."
Since "Havas" requires the accusative -n, the most basic form of this sentence would be "La pico havas oleon." However, when a noun is followed by a preposition like "Da", the accusative -n form does not apply as the oil is not the direct object of the sentence. In turn, "La pico havas multe da oleo." is correct.