Shawarma Spiced Chicken Thighs

Name: Shawarma-Spiced Chicken Thighs
Ingredients: ½ teaspoon ground cinnamon; ½ teaspoon ground coriander; ½ teaspoon ground cumin; ¼ teaspoon smoked paprika; ¼ teaspoon ground cloves; ¼ teaspoon ground turmeric; 3 teaspoons kosher salt, divided; 2 pounds boneless, skinless chicken thighs (about 8 thighs); ½ cup plain whole-milk Greek yogurt; 2 tablespoons mayonnaise; 1 large clove garlic, grated; 3 tablespoons white wine vinegar, divided; 1 ½ pounds tomatoes, quartered; 1 tablespoon fresh oregano leaves, plus more for serving; ¼ teaspoon freshly ground black pepper; ¼ cup olive oil, divided; 1 red onion, cut into ½-inch slices; Naan, for serving