Preheat the oven to 350°. In a small heatproof bowl, soak the dried mushrooms in the water for 10 minutes or until softened. Drain in a sieve lined with cheesecloth or paper toweling over a bowl and serve the liquid. Chop the mushrooms.
In a casserole, melt 2 teaspoons of butter. Add the barley and sauté, stirring, for 1 minute or until lightly browned. Transfer the barley to a small bowl.
Melt the remaining 2 teaspoons of butter in the casserole. Add the onion and sauté, stirring, for 1 minute or until it just begins to turn translucent. Add the fresh mushrooms and sauté, stirring occasionally, for 3 minutes. Return the barley to the casserole, add the soaked mushrooms and their liquid, the stock, salt, pepper and bay leaf, and bring to a boil. Transfer to the oven and bake, covered, for 1 to 1¼ hours or until the barley is tender. Before serving, remove and discard the bay leaf and stir in the chives. Serves 6.