Rinse the pinto beans under cool running water, picking out any stones or debris.
Add the rinsed beans, vegetable broth, water, onion, garlic, chili powder, cumin, black pepper, and bay leaf to the Instant Pot. Stir to combine.
Secure the lid and set the valve to sealing. Select pressure cook (or manual) and set the timer for 45 minutes at high pressure.
When the cooking time is complete, let the pressure release naturally for about 25 minutes. After that, carefully turn the valve to venting to release any remaining pressure.
Open the lid and give the beans a good stir. The beans should be tender and the liquid should have thickened slightly. If there’s more liquid than you’d like for serving, you can ladle some off or simmer the beans on sauté mode for a few minutes to reduce the broth.
Season to taste with salt, stirring well. Remove the bay leaf.
Serve the beans warm, garnished with chopped fresh cilantro if desired.