Combine the chickpeas with the oil, salt, turmeric, pepper and cumin in a bowl and toss to coat well. Transfer to a cast-iron skillet and spread evenly across the pan. Bake the chickpeas until golden brown, about 45 minutes.
Meanwhile, bring the chicken stock to boil saucepan over high heat. Add the lentils, onion, garlic, bay leaf and half lemon. Cook until the lentils are tender, about 18 to 20 minutes; drain. Be sure to discard the lemon, onion, garlic and bay leaf.
Combine the chickpeas, lentils, roasted red bell pepper, and parsley in a medium bowl. Juice the remaining lemon half into the bowl and toss to combine.