Wash and dry the bell peppers thoroughly. Place them in the basket of an air fryer lined with parchment paper and cook for 20 minutes at 350°F (180°C), turning them a couple of times so they roast evenly.

Remove the peppers and, while still hot, place them in an airtight container. Close the container and let them cool until you can handle them without burning yourself.

Once the peppers are warm, remove them from the container, drain off any cooking liquid, peel off the skins, and remove the seeds and stems. Cut the peppers into large strips, then slice them lengthwise into thin strips.

Place the peppers (along with any extra liquid collected during cleaning) in a blender or food processor. Add the extra virgin olive oil, almonds (with or without skins, as you prefer), peeled and finely chopped garlic, chopped fresh basil leaves, a pinch of salt, and, if desired, the hot red pepper powder.

Blend until you get a smooth, creamy pesto. The pesto is ready to use; if not using right away, store in the refrigerator for 2-3 days in an airtight container.