Pumpkin-vegetable stew with couscous

7 cups low-sodium vegetable broth

¹⁄³ cup grapeseed oil

3 medium carrots, peeled, halved lengthwise and then crosswise

2 medium onions, peeled, quartered through the root

1 medium celery root, peeled and cut into 8 wedges

3 large celery stalks, strings removed, cut in large chunks 15-oz can of chickpeas, drained and rinsed 2 tbsp dark brown sugar

4 tsp kosher salt, plus more to taste

3 tbsp sweet paprika

1 tbsp freshly ground black pepper

1¼ tsp ground cinnamon

1 tsp ground mace or ½ tsp ground nutmeg ¼ tsp ground turmeric

¼ cup tomato paste

1½ lbs pumpkin, rind on, seeded, cut in 4-inch chunks

3 small zucchini, trimmed

6 sprigs each fresh dill, parsley, and cilantro, tied in a bundle with kitchen twine

½ very small green cabbage, cut in 4 wedges 2 medium ripe tomatoes, cored and quartered 3 small potatoes, halved