Preheat oven to 400°F (200°C).
In a small bowl, combine lemon zest, lemon juice, dried oregano, dried thyme, half the sea salt, and half the black pepper to create a rub.
Rub the chicken breast evenly with the herb mixture and place it on a parchment-lined baking sheet.
Roast the chicken for 20-25 minutes or until the internal temperature reaches 165°F.
While chicken roasts, heat olive oil in a small saucepan over medium heat.
Sauté the diced onion, carrots, and minced garlic for 3-4 minutes until the vegetables are softened.
Add the dry brown rice to the saucepan and toast for 1 minute, stirring constantly to coat the grains.
Pour in the chicken broth and the remaining salt and pepper; bring to a boil, then reduce heat to low, cover, and simmer for 35-40 minutes.
Stir in the frozen peas during the last 5 minutes of rice cooking time.
Let the rice rest covered for 5 minutes, then fluff with a fork and serve with the sliced roasted chicken.