1.Combine the water and stock in medium saucepan; bring to the boil. Reduce heat; simmer, covered.
2.Heat half the oil in large saucepan; cook pumpkin, stirring, until tender. Add mushrooms; cook, stirring, until mushrooms are tender. Remove vegetables from pan.
3.Heat remaining oil in same pan; cook onion and garlic, stirring, until onion softens. Stir in barley. Add wine; bring to the boil. Reduce heat; simmer, stirring, until wine is absorbed.
4.Add ½ cup of the simmering stock mixture to barley; cook, stirring, over low heat until liquid is absorbed. Continue adding stock mixture, in ½-cup batches, stirring until liquid is absorbed after each addition. Total cooking time should be about 50 minutes or until barley is tender.
5.Add vegetable mixture and sage to risotto; stir until hot. Season to taste.