Soak dried mushrooms in warm water for 30 minutes. Meanwhile, wash hens inside and out; pat dry. Lift mushrooms out of water with a slotted spoon and check carefully for any grit. Strain soaking liquid through a fine sieve lined with paper towels into a saucepan. Add dried mushrooms and 1 Tbsp of butter. Simmer over low heat until all liquid evaporates (about 10 minutes). Divide mushroom mixture among hen cavities. In a small bowl, make a paste with remaining butter, thyme, salt, pepper, and ground bay leaf. Rub mixture over hens, cover with plastic wrap and refrigerate at least 4 hours (or overnight). Preheat oven to 375ºF. Bring birds to room temperature and place them on a rack in a roasting pan. Whisk together garlic, wine and olive oil. Roast hens, basting with wine mixture and pan drippings every 15 minutes. Add sliced mushrooms to pan after 25 minutes and stir to coat with juices. Continue roasting and basting hens and mushrooms until hens are golden brown and juices run clear when birds are pierced with a knife (about 25 more minutes). Remove from oven and let stand 5 minutes. Using a sharp, heavy knife or a cleaver, cut hens in half. Transfer to warm serving plates and surround with fresh and dried mushrooms.

Serves 6