Bring 8 cups of water to boil, add the chicken along with the bay leaves, salt and onion. Cook for 20 minutes until chicken is tender and no longer pink. Remove chicken and set aside. Sift the chicken broth and set aside.
Preheat the oven to 400°F, place the onions on a baking sheet and drizzle 2 tablespoons of the olive oil on top of the onions. Roast in the oven until browned, about 30 minutes.
Pick through molokhia to remove any stems or debris. Soak for 15 minutes and rinse a few times. Squeeze out any liquid and set aside.
Heat the remaining 2 tablespoons olive oil in the pot used to make the chicken broth. Add the cilantro and garlic and cook until fragrant, about one minute.
Add the molokhia to the mixture along with the 7 Spice, coriander, salt and pepper, and saute until the molokhia softens and becomes fragrant, about 5 minutes. Pour the chicken broth on top of the molokhia and cook on medium heat covered for 30 minutes.
Lower the heat to simmer, add the roasted onions, shredded chicken, lemon juice and lemon slices, and simmer for 20 minutes.
Serve warm over Lebanese rice, if desired.