Place a medium-size saucepot over high heat and add 1 1/2 cups of the chicken stock. Bring to a boil then add the peas and the couscous. Place a lid on the pot and turn off the heat. Let sit for 5 minutes.
While the stock is coming up to a boil for the couscous, place a large skillet over high heat with 3 turns of the pan of EVOO, about 3-4 tablespoons. While the skillet is heating up, place the flour on a plate. Toss the chicken in the flour to coat, shaking off any excess. Add the chicken pieces to the hot skillet. Season the chicken liberally with salt, pepper and the lemon zest, and cook for 8-10 minutes, stirring every now and then to get them brown all over.