In a large skillet, over medium-high heat, add oil, onion, couscous and garlic. Stir frequently and cook until couscous is lightly toasted and onions are translucent, about 3-5 minutes.
Trim unwanted fat from the chicken breasts, and cut into thin strips.
Add the chicken strips to the skillet with, stock, lemon zest and juice, basil, parsley, thyme, red pepper flakes, salt and black pepper and stir to combine.
Bring the mixture to a boil. Reduce the heat to medium-low and simmer about 8-10 minutes, until the couscous is al dente, the chicken is cooked through, and some cooking liquid remains in the skillet. If no liquid remains add a small amount of vegetable stock to the skillet as needed.
Stir in Parmesan, peas, tomato paste, and scallions. Let the peas warm through 1-2 minutes.
Garnish with additional Parmesan and pea shoots if desired.