Instructions

for the white sauce

Whisk ¾ cup mayonnaise, ¼ cup plain whole-milk yogurt, 1½ teaspoons water, 1 teaspoon lemon juice, 1 teaspoon sugar, ⅜ teaspoon table salt, ¼ teaspoon garlic powder, and ⅛ teaspoon pepper together in medium bowl. Refrigerate for at least 1 hour or up to 3 days.

for the hot sauce

Microwave ½ cup water and 1 ounce dried arbol chiles, stemmed and seeded in medium bowl until mixture is steaming, about 1½ minutes. Let stand until mixture is cool and arbols have softened, about 10 minutes.
Transfer arbols and soaking liquid to blender. Add 1 tablespoon distilled white vinegar and process until smooth paste forms, about 1 minute, scraping down sides of blender halfway through. Strain through fine-mesh strainer set over medium bowl, pressing to extract as much liquid as possible. Discard solids. Stir in 1 teaspoon sugar, ½ teaspoon salt, ¼ teaspoon smoked paprika, ¼ teaspoon ground coriander, ¼ teaspoon ground cumin, and ⅛ teaspoon garlic powder. Set aside until ready to use. (Hot sauce can be refrigerated for up to 3 months.)

for the chicken and yellow rice

Combine 2 pounds chicken thighs, trimmed; ½ cup plain yogurt; 2 teaspoons lemon juice; 2 teaspoons ground coriander; 1 teaspoon ground cumin; 1 teaspoon garlic powder; 1 teaspoon salt; and ¾ teaspoon pepper in large bowl. Cover and refrigerate for at least 1 hour or overnight.
Adjust oven rack to middle position and heat oven to 400 degrees. Line rimmed baking sheet with aluminum foil and set wire rack in sheet. Using tongs, transfer chicken to prepared rack. Bake until thighs register 165 degrees, about 25 minutes. Let chicken rest for at least 10 minutes.
While chicken is cooking, bring 3 quarts water, 1 tablespoon salt, and 1 tablespoon ground turmeric to boil in large pot over high heat. Once water comes to boil, place 2 cups basmati rice in fine-mesh strainer set over bowl. Rinse under cold running water, swishing with your hands, until water runs clear. Drain rice thoroughly, then immediately add to pot, and boil, stirring occasionally, until just tender, about 9 minutes. Drain and rinse rice in fine-mesh strainer, then transfer to large bowl. Gently fold in 4 teaspoons vegetable oil until all grains are coated. Set aside.
Cut chicken into bite-size pieces. Add to 12-inch nonstick skillet and cook over medium heat until brown crust begins to develop, 4 to 6 minutes.
Divide rice among serving bowls. Top with chicken, drizzle generously with white sauce, and add hot sauce to taste. Divide 4 cups shredded iceberg lettuce and 1 cored and chopped tomato among bowls, nestling alongside chicken, and serve.