Coding Gnome is the Elixir teaching brand of Bruce Tate — author of Seven Languages in Seven Weeks, multiple Elixir books, and one of the most widely cited educators on the Elixir / Erlang BEAM ecosystem. His material is taught at the level of someone who has implemented production systems on the platform across multiple major versions.
The CourseFlix listing carries two Coding Gnome courses: Elixir for Programmers and Elixir for Programmers, Second Edition (the latter covering Phoenix as well). Material is paid and aimed at developers from other backgrounds picking up Elixir as a serious back-end language.