1. Heat oil in medium saucepan over medium heat. Add onion, cook 6 minutes or until soft. Stir in barley. Add wine and cook, stirring, until liquid has evaporated.
2. Add ½ cup stock and cook until liquid is absorbed, stirring occasionally. Continue adding stock ½ cup at a time, waiting until liquid is absorbed before adding more, until barley is tender but still slightly firm, 35-40 minutes. Reserve ¼ cup stock to stir in at the end.
3. About 3 minutes before barley is done, stir in shrimp and peas. Cook until shrimp are opaque throughout. Remove from heat and stir in remaining stock, lemon zest, lemon juice, cheese and salt. Season with pepper and serve.