Serdar Lewis is one of the pre-made NPC chefs in Downtown from The Sims 2: Nightlife. The other two pre-made chefs are Joanne Harris and Calvin Ng. He usually can't be made playable without cheats, unless he is used as a walk-by on a community lot.
Serdar has the same facial structure as Pierce Johnson. His name is randomized when Downtown is generated. The name "Serdar Lewis" is only referenced in the game files. According to his SimDNA in SimPE, his hair was red before it turned grey.