Mısırlı Ahmet studied and practiced drumming in Egypt, hence 'Mısırlı' (the Egyptian).
This involves striking the rim of the drum head (or a bit further down) with a downwards (or diagonal) movement of the index finger of your ornament hand (that is the left hand for right-handed people, or the right hand for left-handed people) and from there, with no extra movement, bringing your ring finger up with a slight twist to strike the rim (or close to the rim).
Also note: a "Tek" is a standard rim hit with the main hand (not ornament).
{The below configuration is for right-handed people; for left-handed the order of the fingers is reversed} 1.
Note 2: There is a more efficient way of doing the split hand technique, which doesn't allow the fingers or wrists to become sore, and doesn't involve as much wrist movement as the above-mentioned way.