Rinse the brown rice under cold water until the water runs clear.
In a medium saucepan, combine the rinsed brown rice and 2 cups of water. Bring to a boil over high heat.
Once boiling, reduce the heat to low, cover, and simmer for 40 minutes or until the rice is tender and water is absorbed. Remove from heat and let it sit covered for 5 minutes.
While the rice cooks, prepare the chicken. Cut the chicken breasts into bite-sized pieces.
In a medium bowl, toss the chicken pieces with olive oil, garlic powder, smoked paprika, salt, and black pepper until evenly coated.
Heat a large non-stick skillet over medium-high heat. Add the seasoned chicken pieces and cook for 6-8 minutes, stirring occasionally, until fully cooked and golden brown.
Add the broccoli florets, diced red bell pepper, and shredded carrots to the skillet with the chicken. Cook for an additional 5 minutes, stirring frequently, until the vegetables are tender-crisp.
Stir in the low sodium soy sauce and fresh lemon juice. Cook for another minute to combine flavors.
Fluff the cooked brown rice with a fork and divide it evenly among four bowls.
Top each bowl of rice with the chicken and vegetable mixture.
Garnish each bowl with chopped green onions before serving.