Light Malt Extract Agar (LMEA)
LMEA is a basic agar recipe that yields excellent results with most cultures. A great beginners agar to make.
Light malt extract is used in beer brewing and is readily available online or at your local homebrewing shop. The powdered form is generally used, and most LMEA recipes you find on the internet assume you're using this version.
A good ratio for LMEA plates is 50/1/1 (water/agar/LME). Some recipes use more LME for higher nutrient plates.
You can scale this ratio up and down to however much agar you wish to produce.
For example, 500ml of water would require 10g agar and 10g LME.
Follow the generic process outlined here.