Rinse the rice under cold water until the water runs clear. Drain well.
In a medium saucepan, bring 4 cups of water to a boil. Add the rinsed rice and 1/2 teaspoon salt. Reduce heat to low, cover, and simmer for 18 minutes or until rice is tender and water is absorbed. Remove from heat and let stand covered for 5 minutes.
While the rice cooks, season the chicken breasts evenly with 1/2 teaspoon salt, black pepper, garlic powder, paprika, and dried thyme.
Heat olive oil in a large skillet over medium-high heat. Add the chicken breasts and cook for 5-6 minutes on each side, or until golden brown and cooked through (internal temperature should reach 165°F). Remove chicken from the skillet and set aside.
In the same skillet, add the chopped onion and minced garlic. Sauté for 3-4 minutes until the onion is translucent and fragrant.
Pour in the chicken broth and scrape any browned bits from the bottom of the skillet. Bring to a simmer and cook for 3 minutes to reduce slightly.
Return the chicken breasts to the skillet and spoon some of the sauce over them. Cook for an additional 2 minutes to heat through.
Fluff the cooked rice with a fork and divide it among four plates. Place a chicken breast on top of each serving of rice and spoon the onion and garlic sauce over the chicken.
Serve immediately.