Cut the jalapeño in half, remove the seeds and the spine from inside the pepper.
Squeeze limes, keep juice and discard rest.
Add all ingredients to a blender and blend until pureed.
Adjust the spices as needed.
Notes
This will make a mild salsa, if you are wanting more heat you can leave in part of the jalapeño spine and seeds.
It is important to not under spice, if you are worried about adding too much spice add a little at a time, you can always add more and blend for a few more seconds.