Put the mortar over a strong enough surface, grab the molcajete and start grind. The main goal is to crush the chili good; God forbid if you let one of those at its whole: devils will be dancing over your tongue.
Even so, one could grind as pleased, not too much, not too little. If you don't have a molcajete stone, nostrichmen, a trick for the blender is to grind by giving ON & OFF pauses to the machine, that way the mix will acquire an approximate of the molcajete texture ;)
https://video.nostr.build/378eb2d40fae0180c11bf9a30137d97b74f0828ecb4c0e50833b1e4c15adecc0.mp4