Mix the first 3 ingredients together in a large bowl, Place to the side.
Slice zucchini into strips lengthwise and red onion into large rings (both about a centimeter thick).
Heat a grill pan to very hot and grill the red pepper (whole), onion rings and zucchini strips. Remove the onion and zucchini when they begin to blacken slightly on the outsides - do no over cook! Continue charring the red pepper until the outside skin is completely black. (This can also be done outside on your BBQ).
While still slightly hot, chop the zucchini and the onion into 1/2 inch pieces and add to the vinegar.
Place the red pepper in a paper bag and allow the steam loosen the skin. After a couple of minutes, remove the peel and the seeds. Chop the pepper into 1/2 inch pieces and add to the vinegar.
Toss the grilled veggies in the vinegar dressing and cover the bowl with plastic plastic wrap (to trap the remaining steam inside).
Cook the couscous according to the manufacturer using the chicken stock. I have provided the measurements for a "quick cooking" couscous, you may need to add more/less liquid according to the brand you use.
After cooking, fluff the couscous with a fork and add to the bowl with the grilled veggies and vinegar dressing.
Add the cheese, tomatoes and olives. Toss to incorporate all ingredients well.
Chill. This recipe can be made a day in advance. Lightly toss the salad before serving to give it a light texture.