Return broth to the pot. Add 1 cup of water and 2 tablespoons extra-virgin olive oil and bring to a boil. Reduce heat and add 2 cups couscous. Cover pot and remove from heat. Let rest for 10 minutes, allowing the couscous to absorb all the liquid. Fluff with a fork and season with salt and pepper.
In a large skillet, add the remaining 1/4 cup oil and the 2 cloves of minced garlic. Heat the oil, making sure not to burn the garlic. When the oil is hot, add the shrimp and stirring occasionally, cook the shrimp until they start to turn pink, about 5 minutes. Be careful not to overcook the shrimp or they will become tough. Remove from heat and add the lemon juice, red pepper and chopped parsley. Check for seasoning.
To serve, mound the couscous in the center of a platter and top with the shrimp.