In a small mixing bowl, whisk together the olive oil, ground cumin, coriander, turmeric, garlic powder, sea salt, and black pepper to create a spice paste.
Slice the chicken breast into thin bite-sized strips and toss thoroughly in the spice paste until every piece is well coated.
Heat a non-stick skillet over medium-high heat and add the spiced chicken strips, sautéing for 6-8 minutes until golden brown and fully cooked.
Prepare the dressing by whisking the tahini and lemon juice in a small jar, adding a teaspoon of warm water at a time until it reaches a smooth, pourable consistency.
Dice the cucumber, halve the cherry tomatoes, and finely mince the red onion.
Place the warm cooked brown rice in the center of a bowl and arrange the cooked chicken and fresh vegetables on top.
Drizzle the creamy lemon-tahini sauce over the entire bowl and enjoy immediately.