In a large bowl, whisk ¼ cup yogurt, olive oil, cumin, coriander, paprika, turmeric, cinnamon, salt, pepper, and 2 minced garlic cloves. Add chicken and coat well. Let sit at room temperature for 15 minutes.

Heat a drizzle of oil in a large skillet over medium-high heat. Sear the chicken thighs in a single layer for 4 to 5 minutes per side until golden and cooked through (165°F). Let rest on a cutting board.

Rinse the rice, then combine with 1 ¾ cups water and a pinch of salt in a saucepan. Bring to a boil, cover, reduce heat to low, and simmer 15 minutes. Remove from heat, let sit 5 minutes, then fluff.

Slice the chicken against the grain. Whisk the remaining ¼ cup yogurt, the reserved minced garlic clove, and lemon juice for the sauce. Divide rice among bowls, top with chicken, tomato, cucumber, red onion, and parsley. Drizzle with garlic sauce and serve.