1. In a saucepan, heat 1 tbsp (15 mL) of the oil over medium heat for 30 seconds. Add onion and bell pepper and cook, stirring, until softened, about 5 minutes. Add saffron liquid, water and tomatoes with juice and bring to a boil. Stir in couscous. Remove from heat and let stand, covered, for 15 minutes. Fluff with a fork.
2. In a skillet, heat remaining 1 tbsp (15 mL) of oil over medium-high heat. Add shrimp and cook, stirring, just until they turn pink and opaque, 3 to 5 minutes. Add garlic, lemon zest, cayenne and black pepper to taste. Cook, stirring, for 1 minute. Add white wine and lemon juice and bring to a boil. Stir in peas until heated through. Season to taste with salt, if using.
3. To serve: On a deep platter, arrange couscous in a ring around the edge, leaving the center hollow. Arrange shrimp in the center.
Peppery Shrimp with Millet: Substitute an equal quantity of millet for the couscous. For the best flavor, before using in the recipe toast it in a dry skillet, stirring until fragrant, about 5 minutes. Stir the millet into tomato mixture (Step 1) and return to a boil. Cover and simmer over low heat for 20 minutes, then remove from heat and let stand for 10 minutes.
Peppery Shrimp with Quinoa: Substitute an equal quantity rinsed quinoa for the couscous. Stir the quinoa into the tomato mixture (Step 1) and return to a boil. Cover and simmer over low heat for 15 minutes. Remove from heat, cover, and set aside for 5 minutes. Fluff with a fork before using.