Preheat oven to 400°. Cook brown rice according to directions. Combine soy sauce and cornstarch in a small saucepan, stirring with a whisk. Add brown sugar, mirin, and lemon juice; bring to a boil. Cook 1 minute or until thickened. Sprinkle chicken with salt and pepper. Heat a large ovenproof skillet over medium-high heat. Add canola oil to pan; swirl to coat. Add chicken to pan; cook 4 minutes. Turn; drizzle 1 tablespoon soy sauce mixture over chicken. Place pan in oven; bake at 400° for 8 minutes or until done. Place chicken on a cutting board; let stand 5 minutes. Cut chicken into slices. Bring a large saucepan of water to a boil. Add Broccolini; cook 3 minutes or until crisp-tender. Drain. Place 1/2 cup rice in each of 4 bowls; top each serving with 4 ounces chicken and 4 ounces Broccolini. Drizzle about 1 tablespoon remaining soy sauce mixture over each serving.