Preheat the oven to 375. Add butter to a large pot/pan over medium-low heat. Make sure the pot/pan is stove AND oven safe. Add brown rice and cook 1-2 minutes until it starts to toast. Add chicken broth and cilantro. Cover and let simmer for 10 minutes while we prepare the chicken.
Mix up the yogurt sauce. Combine all the ingredients for the sauce (plain greek yogurt, cilantro, lemon juice, garlic salt, paprika, cumin, black pepper) in a small bowl and stir to combine.
Pat the chicken thighs dry with a paper towel. With the skin side up, rub 1 tbsp of yogurt sauce on the top of each chicken thigh. Set remaining yogurt sauce in the fridge until serving.
Uncover the rice and transfer the chicken thighs to the pan. Nestle each thigh in the brown rice. Cover the pan and transfer to the oven.
Cook for 25-30 minutes, until the internal temp of the chicken reaches 165 F.
To serve, spread a scoop of the remaining yogurt sauce onto each plate. Top with brown rice, a chicken thigh, tomato, and red onion. Enjoy!
Keep any leftovers in a sealed container in the fridge. It will keep for 3-4 days.