Combine broth, water and oil in a large saucepan; bring to a boil. Stir in couscous and remove from heat. Cover and let plump for 5 minutes.
Meanwhile, cook peas on the stovetop or in the microwave according to package directions.
Add the peas, dill, lemon zest, salt and pepper to the couscous; mix gently and fluff with a fork. Serve hot, sprinkled with cheese.