heat veggie oil in a large pot until shiny, add the veggies, onion and garlic at medium heat until the onions become "glassy" (about 10 min). Then add split peas and barley (ratio of 2:1), salt and about six times the amount of water as split peas (so one cup split peas means 1/2 cups barley, 6 cups water, 1.5 tsp salt). Bring this to a boil then cover and simmer for at least one hr. I recommend waiting until the split peas have essentially disintegrated. If you want a thicker soup, remove the lid and continue cooking; the water will evaporate. Add salt, pepper and other herbs to taste (I liked adding rosemary from the plant I then managed to kill--not enough water...oops!) and...Enjoy! It's perefct for the cold weather that has now arrived.
(I apologize for the lousy picture; I forgot to photograph the soup before storing the leftovers)