Sentence:  The ungrateful “they” are Brooklynites who've come to see Harding-Mamary creations as a chain, where you can get it venti in a ramekin with crème fraîche or <WSD>slushed</WSD> with guava and salt on the rim. 
Meaning of the word marked with <WSD> tags:  To smear with slushy liquid or grease.