Make the pesto: In the bowl of a food processor, pulse together the basil, 1 tablespoon garlic, walnuts, and Parmesan cheese. With the food processor running, slowly drizzle in cup oil. Season with salt and pepper.

Make the couscous: In a medium saucepan over medium-high heat, bring 2 cups of water and 1/2 teaspoon of salt to a boil. Remove from the heat, stir in the couscous, cover, and let stand for 5 minutes, or while you cook the shrimp. When you are ready to serve, stir half the pesto into the couscous.

Cook the shrimp: In a large skillet over medium heat, add 1 tablespoon oil, 1 tablespoon garlic, and red pepper flakes, and cook for 30 seconds. Add the broth and lemon juice, and cook until it bubbles. Add the shrimp, season with salt and pepper, give it a good stir, and cook until the shrimp is pink and cooked through, about 3-4 minutes. Remove the pan from the heat and stir in the parsley. Serve immediately, spooning the shrimp and sauce over the Pesto Couscous.