Preheat oven to 400°F.
Place the barley and vegetable broth in a medium saucepan and bring to a boil. Cover and reduce to a simmer. Cook until barley is soft and chewy (cooking time will vary depending on the type of barley used). Transfer the barley to a large mixing bowl.
Toss the carrots with 2 teaspoons olive oil on a baking sheet. Toss the chickpeas with 2 teaspoons olive oil on a second baking sheet.
To make the spice mix, mix the cumin, turmeric, paprika, and salt in a small bowl.
Toss the carrots with half of the spice mix and toss the chickpeas with the other half of the spice mix. Roast the carrots and chickpeas in the oven until crisp tender, 20-25 minutes. Remove from oven and add to the bowl with the barley.
To make the dressing, whisk the lemon juice, tahini, garlic, olive oil, water, salt and pepper together in a bowl.
Add the dressing and the parsley to the bowl and stir to combine all ingredients. Adjust seasoning to taste. Transfer to a serving platter and top with pistachios and extra parsley.