Add the carrots, purple sweet potatoes, salt, black pepper, crushed tomatoes. Cook, stirring, for about a minute, until fragrant, and add the broth and bay leaves. Bring to a simmer, and simmer until the sweet potatoes and carrots have cooked down slightly, about 10 minutes. Reduce heat to low, simmer uncovered, for about 20 minutes. Meanwhile, cook the Israeli cous cous or grains, grate lemon rind; chop parsley.
Add the saffron threads and chickpeas to the pot. Reduce to a simmer and cover with a lid. Simmer 10 minutes. Add the yellow bell pepper and cook another 2 minutes.
Remove bay leaves and cinnamon stick before serving and add cous cous or your favorite grain. Ladle into bowls and top with chopped parsley (if desired), grated lemon zest and a drizzle of olive oil.
The stew is moderately spicy. For very spicy, use 2 to 2½ tablespoons harissa. For mildly spicy, use 1 tablespoon harissa.
Purple Sweet Potato substitutions: Any potatoes, squash, pumpkin, turnips, or cauliflower. If you are using winter squashes or butternut, I recommend steaming them and adding them in the end.
Chickpea subsitutions: Use canned Cannellini, Great Northern and Navy beans if you like, but add them at the same time as the sweet potatoes & carrots and the beans will absorb the flavors of spices while cooking.
Source : Vegan Miam