Spiced Chicken and Chickpea Stew

Name: Spiced Chicken and Chickpea Stew
Ingredients: 1⁄4 cup canola oil; 6 cloves garlic; 3 small onions, quartered; 4 medium waxy-style potatoes, peeled and quartered; 2 bay leaves; 2 tbsp. Spice Mixture; 1 tbsp. ground tumeric; 1 tbsp. kosher salt, plus more to taste; 4 skinless chicken legs (about 1 lb.); 4 skinless chicken thighs (about 1 lb.); 1 (19-oz.) can chickpeas, drained; 4 pieces khubuz al-tannour (Iraqi flat bread), naan, or pita; 1 lemon, quartered; 1 tbsp. dried sumac (optional)