Suor Clerici Achievement in Vampire Survivors

This is cumulative across all runs. There are three ways to recover HP during runs:
 

• Buy and upgrade the powerup between runs that grants you HP recovery
• Find and choose the Pummonia item during runs, which grants HP recovery
• Evolve the Garlic. Its evolution grants life steal every time it hits an enemy
• Evolve the Whip. Its evolution grants life steal every time it hits an enemy

All of these things will progress this achievement, but you'll find that the first time you evolve the Garlic, you will probably unlock this achievement that same run. The evolved Garlic has a huge radius and steals HP like crazy, so if you haven't unlocked this achievement by then, evolve the Garlic and you'll get this achievement very quickly.