Preheat oven to 400°F and line a 9x13-inch baking pan with parchment paper. Place carrots, bell pepper, tomatoes, onion, garlic and 1/8 teaspoon salt in the pan and toss. Bake in the top third of the oven until vegetables are tender, about 25 minutes.
Stir vegetables, arrange fish on top and sprinkle with remaining salt, lemon zest and juice and bake until fish is just cooked through, 15 to 20 more minutes. Transfer fish and vegetables to plates or a platter along with quinoa and sprinkle with cilantro and pine nuts.
*Use precooked frozen quinoa or cook from scratch by rinsing 1 cup quinoa in a fine sieve until water runs clear, drain and transfer to a small pot. Add 2 cups water and bring to a boil. Cover, reduce heat to medium low and simmer until water is absorbed, 15 to 20 minutes. Set aside off the heat for 5 minutes; uncover and fluff with a fork.