Moroccan Couscous

Name: Moroccan Couscous
Ingredients: 1 cinnamon stick; 1 teaspoon black peppercorns; 1/2 teaspoon white peppercorns; 1 teaspoon cumin seeds; 1 teaspoon coriander seeds; 1 teaspoon whole allspice; 1/2 teaspoon whole cloves; 2 cardamom pods; 1 teaspoon ground ginger; 1 teaspoon turmeric; 1/4 to 1/2 teaspoon cayenne pepper; 1/2 teaspoon freshly grated nutmeg; Kosher salt; 3 tablespoons unsalted butter; Large pinch of saffron (optional); 2 1/4 cups (12 ounces) whole-wheat couscous; 3 cups low-sodium chicken broth, warmed; 1 to 2 teaspoons fresh lemon juice