Melt the butter in a 8-10" skillet over medium heat.
Stir in the onion. Sauté for about 5 minutes.
Add in the mushrooms. Saute another 5 minutes - until the onions are golden and the mushrooms tender.
Add the barley and cook, stirring occasionally until the barley is light brown (5-10 minutes).
Transfer the mixture to a lightly greased 2 quart casserole dish. Add the broth, salt, cayenne and parsley.
Cover and bake for 50 minutes or until the liquid is absorbed.
This recipe originally appeared in The California Heritage Cookbook (now out of print). This dish works out best when prepared in a casserole dish with a lid.Vegan Adaption: Use vegan butter substitute and vegetable broth.