In a bowl, mix together shrimps, 1 tablespoon of olive oil, and mixed herbs. Season with salt and pepper and let it marinate while you cook the couscous.
Heat the remaining 1 tablespoon of oil in a pan over high heat; once hot, toss in bell peppers. Sear for 3-4 minutes, or until the edges are browned.
Remove from the pan and set aside.
In the same pan, add the shrimps and cook for 3-4 minutes, stirring often, until cooked through. Remove from the pan and set aside.
Reduce the heat to medium, and let the pan cool slightly. Add couscous and toast for 1 minute. Season with mixed herbs and add in the minced garlic. Mix well.
Now pour in the chicken stock, then reduce the heat to a low simmer.
Cook covered for 6-8 minutes, until most of the liquid has been absorbed.
Add in the chopped tomatoes, cooked shrimps, peppers, lemon juice and zest. Stir well, then cover to cook for another 5 minutes until everything is heated.
Garnish with basil and serve.