Chicken Shawarma with Potatoes

Name: Chicken Shawarma with Potatoes
Ingredients: 2 tablespoons lemon juice; 2 tablespoons olive oil, divided; 2 cloves garlic, minced; ½ teaspoon ground cumin; ½ teaspoon salt; ¼ teaspoon ground cinnamon; ¼ teaspoon ground turmeric; ¼ teaspoon ground pepper; 12 ounces Yukon Gold potatoes (2 medium), peeled and cut into 1/2-inch chunks; 1 medium red bell pepper, sliced; 1 small onion, thinly sliced; 12 ounces boneless, skinless chicken thighs, trimmed; Chopped fresh parsley or chives for garnish