In a large pot over medium heat, heat oil and cook leeks until they begin to brown, 10 to 12 minutes.
Step 2
Finely chop cilantro stems. Stir into pot, along with diced fennel and garlic. Cook for 2 minutes. Stir in baharat, cinnamon and tomato paste, and cook until paste begins to caramelize, about 2 minutes.
Step 3
Stir in broth, 3 cups water, the barley and the salt. Bring to a gentle boil, stir in saffron, if using, and reduce heat to medium. Simmer uncovered for 40 minutes. Stir in beans, squash, turnip and lentils; cook until barley is tender, about another 20 to 30 minutes. Taste and adjust seasonings, if desired. Remove cinnamon stick.
Step 4
Ladle stew into bowls. Spoon a dollop of yogurt on top and drizzle with olive oil. Garnish with cilantro leaves, fennel fronds and Aleppo pepper or paprika.