1. In skillet, heat olive oil. Saute mushrooms, onions, and garlic until starting to soften (4-5 minutes).
2. Add remaining ingredients except parsley. Cover and simmer until fish flakes easily with fork (8-10 minutes).
3. Remove fillets to warm platter. Pour vegetables over fish and top with parsley to serve. If you like, lemon and paprika make lovely garnishes.