A cauldron can be used for crafting Potions in frozen flame.
How to Unlock the Cauldron in Frozen Flame
Once you have obtained both Solid Essence and Iron Ore, the Cauldron will become available to you to use in Frozen Flame. The cultivation of Magic Essence is the means via which one can gain Solid Essence. Since Iron Ore is located in the Broken Valley, you won’t be able to access it until after you’ve successfully taken down the first monster in the area.
In Cauldron you can Craft following Potions