Rinse the quinoa under cold running water using a fine-mesh strainer to remove any bitterness.
Add the rinsed quinoa, water (or broth), salt, pepper, olive oil, and garlic (if using) to the Instant Pot.
Close the Instant Pot lid, ensuring the steam release handle is set to the sealing position.
Press the 'Manual' or 'Pressure Cook' button and set the cooking time to 1 minute at high pressure.
Once the cooking cycle is complete, allow for a natural pressure release for 10 minutes. Then carefully switch the steam release handle to the venting position to release any remaining pressure.
Open the lid, fluff the quinoa with a fork, and taste for seasoning. Adjust as necessary.
Serve warm, garnished with fresh herbs if desired.