Cooking Master Boy (manga) is divided into two sections:

• Chuuka Ichiban - 5 volumes
  
• Shin Chuuka Ichiban - 12 volumes

You could say that "Shin Chuuka Ichiban" is a completely new arc/sequel. It mainly deals with that Underground Cooking Society.

Chapter where anime approximately ends: Shin Chuuka Ichiban Volume 07 Chapter 59 (or Cooking Master Boy Volume 12 Chapter 59)

The anime ends at differently from that chapter.

T/N: Translation Notes
CKM Scans has tried to keep names and places consistent with the anime. For example, 'Szechuan'. Technically, I'd say 'Sichuan', but that wouldn't be consistent with previous scanlated chapters, the anime or the wikipedia definition etc.

So yeah, I just felt like explaining some stuff.