Conjure Mana Potion

2nd-level Conjuration
Casting Time: 1 action
Range: Touch
Components: VSM (a containment vessel to carry the potion)
Duration: Until you complete a long rest

This spell fills an empty vessel with a bright blue, minty-tasting bitter draught. If a spellcaster consumes this potion, it restores 2 mana.
At Higher Levels. When you cast this spell using a slot of 3rd level or higher, it restores a number of mana equal to one spell slot's mana cost less than the spell used. So a 3rd level conjure mana potion spell restores 3 mana, and a 4th level restores 5 mana, and so on.

Source: Homebrew