In a Dutch oven or large sauce pan over medium heat, add 1 tbsp of olive oil. Add 1⁄2 cup of diced onion and cook until translucent, stirring occasionally, about 4 minutes.
Add chicken breasts to the pan. Add the saffron, cumin, turmeric, paprika, garlic, ginger, salt, and pepper. Using tongs, turn the chicken in the spices and aromatics to coat well. Cook for 3 to 5 minutes, giving the spices time to open up and season the chicken.
Add the tomato purée, tomato paste, chicken broth, carrots, mushrooms, sliced onion, cilantro, and parsley, and let cook for 10 minutes.
Add the zucchini and heirloom cherry tomatoes to the pan and cook for another 10 minutes or until vegetables are tender.
Meanwhile, to make the couscous:
Preheat oven to 350°F. Add couscous to a 3-quart rectangular baking dish (about 9 by 13 inches), drizzle with 1/4 cup of olive oil. Using a spoon, mix the couscous and olive oil together well and add salt and pepper as desired. Add 4 cups of water to the couscous. Cover pan tightly with aluminum foil.
Put the couscous in the oven cook and cook for 15 to 18 minutes, or until tender. Remove from oven and fluff the couscous with a spatula. Drizzle with 1 tablespoon of olive oil.
Transfer to a large bowl and continue to fluff and mix together with a whisk, or, if you feel like it, use your hands to break any clumps of couscous into single grains. Add lemon juice, butter, almonds, and raisins. Mix together again and fluff with hands. Return couscous to the oven at 350°F for 5 minutes then serve.