When you finish a Short Rest, you can perform a blood ritual to expend Hit Point Dice and recover expended level 1-5 spell slots. The cost for each spell slot is given on the Hemomantic Recovery table.
Once you use this feature, you can't do so again until you finish a Long Rest.
Hemomantic Recovery
| Spell Level | Hit Dice |
|---|---|
| 1 | 2 |
| 2 | 3 |
| 3 | 5 |
| 4 | 6 |
| 5 | 7 |