In a sauce pan over medium heat, add couscous, chicken broth, lemon juice and basil. Cover with lid and cook for 20 minutes.
In a large saute pan over medium-high heat, add butter, garlic, red pepper flakes and parsley. Once melted, add shrimp. Cover with lid, reduce heat to medium and let cook until couscous is done.
Remove lid from couscous and stir in lemon zest and parmesan cheese. Then add couscous to saute pan with shrimp. Toss to coat and cook another 3-5 minutes - stirring regularly.