Step 1

Pour 3/4 cup olive oil into each jar. Place rosemary in one jar, oregano in another, and crushed red pepper flakes in the third. Screw lids on to seal.

Step 2

Pour 4 cups water into a multi-functional pressure cooker (such as Instant Pot®) and place jars in the water. Close and lock the lid. Select high pressure according to manufacturer's instructions; set timer for 0 minutes. Allow 10 to 15 minutes for pressure to build.

Step 3

Release pressure carefully using the quick-release method according to manufacturer's instructions, about 3 minutes.

Step 4

Remove the lid and let jars cool for 30 minutes before handling. Strain oil into bottles and seal.