One of the staples of my vegan experiment was this Mushroom Barley Bake, easy to make and very hearty.
1 large (or 2 small) onion chopped
1-2 cups sliced/chopped mushrooms
1 cup barley
3 cups vegetable broth
red chili flakes
Saute the mushrooms and onions in olive oil. Don't overdo it, just saute them until the mushrooms release a bit of water and the onions become clear.
Bake at 350F for 90 minutes. I think I had the lid on for half of the time, but I can't remember if it was at the beginning or the end. Use your judgement.
Here it is right out of the oven. As with virtually everything I cook - it freezes well so this is a good one to make a double batch of. This is a great vegan/vegetarian dish, but also makes a hearty side dish to roast chicken.