Warm the butter in a large saute pan over a medium low heat.
Once the better has fully melted, add in the salt and the garlic. Cook over the low heat for about 1 minute, until it becomes aromatic. Don't let the garlic brown, so reduce heat if need be.
Add in the pepper flakes. Saute for 1 minute.
Trim off the asparagus ends, rinse and add the asparagus to the pan. Turn the heat up to medium.
Mix all of the asparagus, so it is fully coated by the butter. Cook for about 3 minutes, until the asparagus becomes bright green and just tender.
Plate with all of the extra butter, garlic and pepper flakes.