Add the brown rice, water, turmeric, garlic, ginger, salt, and pepper to a small saucepan. Bring to a boil over medium heat.
Cover, reduce to simmer, and simmer for 15 minutes. Remove from heat, and let sit, covered for an additional 10 minutes.
Meanwhile, make the chicken. Add the cubed chicken breast, olive oil, harissa, and garlic to a bowl, mixing to combine.
Heat a non-stick pan over medium heat. Add the chicken to the pan, cooking for 8 to 10 minutes, or until fully cooked. Set aside.
Make the dressing: whisk together the tahini, water, parsley, lemon zest, and juice. Add water, 1 tablespoon at a time, as needed, to reach desired consistency. Note: if making in advance, it will thicken slightly, add water before serving.
Divide the cucumber, tomatoes, and arugula into the bowls. Top with chicken, turmeric rice, and drizzle with tahini.