A gomlek is the inner most layer, the chemise portion of a Turkish ensemble. They have full length sleeves and are below knee to floor length. Often they are embroidered. The front features a round neckline that sits on the collarbone, with a long slit to the navel, held closed by a tie or a small button. The side gore is gathered into the waist, which gives additional bulk to the hips to support the outer layers of costume.
Unfortunately we have no surviving examples of a period gomlek, and no art showing this layer by itself due to modesty. I used a suggested construction method commonly used by others in the Ottoman costuming community to pattern this. I have also included a line art drawing of the pattern below and some other examples.
Türkisches Kostümbuch, c. 1574
This image show the relatively narrow sleeve. Many gomleks have wider sleeves, but I chose narrow for practicality reasons.
John White, pre-1593
This image shows the split front neck, allowing her breasts to be exposed at the front.
Johannes Lewenklaw, 1585
Second from the right, we see a slightly shorter gomlek peeking out from under her caftan.
Post-period Extant garment
This is a post-period extant garment (19th c.), however it does give a great example of the construction.
The Album of Ahmed I, 1620