Possibly the Greatest Alchemist of All Time Izure Saikyou no Renkinjutsushi?

A salaryman is surprised to find himself summoned to another world by accident. With no way of returning to Earth, he receives the name Takumi Iruma, a different younger body, magic powers, and a fresh start in an unfamiliar land. To preserve his quiet life, Takumi settles in a local village and assumes the job of an alchemist, allowing him to create almost anything he desires. Making the most of his time, he explores his new abilities and even tames an unlikely pet.

However, Takumi decides to move on to a big city in hopes of improving his alchemy skills and business. As he keeps learning about his profession and gaining new connections, Takumi might just be able to become the greatest alchemist of all time.

[Written by MAL Rewrite]