Bring vegetable broth and quinoa to a boil in a saucepan over medium heat. Reduce heat, cover, and simmer until quinoa is tender and the water has been absorbed, 15 to 20 minutes. After 10 minutes of cook time, add carrots and cook for the last 5 to 10 minutes with the quinoa. Remove from heat, drain, and place in a bowl.

While quinoa is cooking, heat 2 tablespoons olive oil in a skillet. Add zucchini and cook, stirring frequently, until softened and browned, about 5 minutes. Lightly salt. Remove and add to quinoa. Mix in scallions.

Mix lemon juice, 2 tablespoons olive oil, salt, and pepper in a small bowl for the dressing; pour over the salad. Add cucumber and dill and toss to combine.