There's an easily missable document at the start of the quest (can't be viewed later after you start Rinascita's quest). It's a Bloom Bearer's report on Rinascita consisting of four observations/rules... the fourth being never put crownapple (pineapple) on pizza.
ETA 1/20/2025: I was able to dig up the exact text:
4. Ragunna has one cardinal rule regarding pizza: it does not, and will never, tolerate crownapple topping. Do NOT in any circumstance, add crownapple or gemberry to any pizza served at a Ragunnesi restaurant. This rule must-and I repeat-must be adhered to.
Updated