1. Warm oil in a large nonstick saucepan over medium-high heat. Add ginger and garlic; cook, stirring, until fragrant, about 1 minute. Add shrimp and cook, stirring frequently, until just pink, about 3 minutes.
2. Stir in couscous, 1 1/4 cups water, peas and salt, raise heat to high and bring to a boil. Remove pot from heat, cover and let stand until couscous is tender and liquid has absorbed, 10 to 12 minutes. Stir in lemon juice and serve.