Preheat the oven to 350. Plump the currants in the orange juice for 20 minutes. In a large Dutch oven with a tight fitting lid, heat the olive oil over medium heat. Add the garlic and onion and saute for 5 minutes. Add the mushrooms and saute for 3-5 minutes, until softened. Add the barley, wheat berries, millet, wild and brown rice. Stir to coat with the oil and cook, stirring, for 10-15 minutes. The grains should be soft to the tooth. Stir in the chicken brothand bring to a boil. Cover and place in oven; bake for 30 minutes. Remove the pilaf from the oven; stir in the scallion, currants and soaking liquid, toasted almonds, and parsley. Season with salt and pepper to taste. Serve immediately.