Add couscous, water, smashed garlic, and salt to a stock pot.
Bring to a boil over medium high heat, stirring occasionally so the couscous doesn't stick together or to the bottom of the pot.
Once boiling, reduce heat to medium low and add the peas and 1/4 c chicken broth to the pot. Continue cooking until couscous is al dente and liquid has been absorbed into a creamy sauce (about another 8-10 minutes). If your couscous seems to be soaking up the liquid too quickly, and it's not finished cooking, add an additional 1/4 c of broth and cook until al dente.
Turn off the heat and stir in parmesan until melted and incorporated. Sprinkle zest over the top, serve up and enjoy!