Place the vegetable stock in a medium-sized saucepan and bring it to a boil.
Take the stock off the heat, stir in the couscous then put the lid on the pan.
Allow the couscous to sit with the lid on for about 10 minutes until the liquid has been absorbed.
Preheat oven to 350 F.
While your couscous is sitting, cut the peppers in half and pull out the seeds and ribs, then set aside.
When the couscous has finished sitting, fluff it with a fork and place it in a large bowl with the diced tomatoes, feta cheese and diced olives. Stir gently until combined.
In a separate small bowl, whisk together the lemon juice, olive oil, basil and chopped fresh parsley. Pour over the couscous mixture and toss gently.
Spoon couscous into each pepper half, and sprinkle with a dash of salt and pepper. Sprinkle on some parmesan cheese.
Roast the stuffed peppers for about 35 minutes or until peppers are just barely tender.
Cool for about 10 minutes before serving.