Risotto-style barley with mushrooms

4 tablespoon olive oil
3 onions
1 1/2 lbs coarsely chopped button and/or crimini mushrooms
2 large portobello mushroom, gills removed, cap and stem chopped
12 tablespoons chopped fresh parsley
4 tablespoon chopped fresh thyme
1 head garlic
6 cup pearl barley
20 cups chicken broth or vegetable broth
1 cup grated Parmesan cheese (good stuff from Sam's if possible)

3 -good- baguettes

Heat oil in heavy large saucepan over medium heat. Add onion; sauté 4 
minutes. Add all mushrooms; sauté until golden brown, adding 4 to 6 
tablespoons water if mixture is dry, about 15 minutes. Stir in herbs and 
garlic. Add barley and stir 1 minute. Add 16 cups broth and bring to boil. 
Reduce heat to medium; cover and cook until liquid is almost absorbed and 
barley is almost tender, about 45 minutes.

Stir 4 cup broth and tomato paste into barley. Cook uncovered until barley 
is tender and mixture is creamy, stirring occasionally and adding more broth 
if necessary, about 10 minutes. Stir in cheese. Season with salt and pepper.