That Time I Got Reincarnated as a Slime: Gourmet Story - Peko and Rimuru's Cooking Book

This Spinoff starts from Volume 3 of Light Novel, after the Orc Lord arc.

Peko is a goblin who has given up being a warrior and turned to the world of cooking to satisfy the hunger of others. With a unique cooking skill called Glutton, Peko will discover new types of food for Tempest, and so begins the Tensura Gourmet Spinoff!