I have often wondered about those ingredients myself, if there was some way to farm them, or if they were just rare/limited items. I have never found a Tyrean Dried Tulip in this particular game. The only time I've ever found them was in LP1, where they were sold by a traveling merchant in the SankT Leona Hill Valley the first time you pass through it. After exiting that shop menu, the merchant claims they are going to Tangar Village, but you never see them again, so it seems to be a one-time oppurtunity!
I know Angel Nuts are dropped by Angel Assassins, and Fruits of the Mist are dropped by Ancient Nautilus, but sadly, I have never found any respawning or random encounters of them! I would definitely like to know more about that too, to include it in my walkthrough!
The only one that I know that you can get in infinite amounts are Ocean Conchs. After defeating Rixian, and before Metrolia is... made inaccessible, Baretta willl sell you a pack of Nenula's Powder and Ocean Conch for 2000 pp, and also a pack of a Heart of the Town and a Diamond of Zerox for 2800 pp, and you can buy as many of them as you want!