Forget-Me-Not
From Hades 2 Wiki and Guides
Useful Pages:
Nocturnal Arms, their Aspects & Upgrades
All the Boons
Hades II Guides
After completing the Forget-Me-Not Incantation, you can set reminders on recipes you wish to save up for at the Cauldron, Altar of Ashes, and Silver Pool. When encountering a Door Preview, a 
Forget-Me-Not icon will show up if Melinoë does not yet have enough of that resource for all of her saved recipes. You can also access all marked recipes from the Inventory Screen, to review exactly what you need for any particular recipe.