In a large pot combine water, bouillon cubes and barley. Wash the mushrooms and break into pieces. Then add them to the pot. Add salt and fresh ground pepper. Cover, bring to a boil and reduce heat to a simmer. Cook for about 20 - 30 minutes or until all the water the absorbed. I like my barley a little firmer, but you can add more water if you want it mushier. Take off the heat and let stand at least 5 minutes before serving.