1. Random, rare drop from all monsters except if they have 100% drop rate for their main drop
2. Can grow in the clover field at the farm. Seems to be based off of kills or playtime?
3. Can probably be given by the NPC at the farm that collects mats as well? Amount increases based on the last time you interacted with them
Next two are just for completions sake. Don't worry about them for now because you're better off just running around killing things than actively trying to farm them from these
4. Okokkori has a main drop of broccoli, very low chance. Randomly found at END, fixed spawn at Castle Ruins B1 and Room of Secrets
5. White Okokkori has a main drop of white broccoli, also extremely low chance. The boss rarely spawns every 1000 floors at END, you'll need to do a ton of grinding for other rare drops to even reliably encounter it