Marinate the Chicken: Clean the chicken thighs and place them in a large bowl. Add crushed chicken bouillon, garlic powder, cayenne pepper, onion powder, olive oil, and lemon juice. Mix well, cover, and refrigerate for at least 1 hour.

Prepare the Vegetables: Preheat the oven to 400°F (200°C). Chop fresh vegetables into bite-sized pieces, arrange them on a baking dish with thyme and olive oil, toss to coat, and roast for 30-35 minutes until caramelized.

Roast the Chicken: After marinating, place the chicken thighs in a baking dish and roast in the oven for 40-45 minutes until golden brown and cooked through to 165°F (74°C).

Make the Sauce: Once the vegetables are roasted, blend them with any juices until smooth, and set aside.

Prepare the Rice Mixture: In a casserole dish, combine blended sauce with rinsed rice, tomato paste, and enough water to cover the rice. Add remaining spices and cover tightly with foil.

Bake the Rice: Lower oven temperature to 350°F (175°C) and bake for 50-60 minutes until rice is tender and liquid is absorbed. Let sit covered for a few minutes.

Serve and Garnish: Fluff the rice gently with a fork, arrange chicken on top, and garnish with herbs and lemon slices.