Dice the chicken breast into bite-sized pieces and place in a bowl.
Toss the chicken with the cumin, coriander, paprika, turmeric, sea salt, black pepper, and half of the lemon juice.
Heat the olive oil in a large skillet over medium-high heat and sauté the chicken until golden brown and cooked through, about 7 minutes.
In a small bowl, whisk together the Greek yogurt, tahini, minced garlic, and the remaining lemon juice until the sauce is creamy.
Dice the cucumber, halve the cherry tomatoes, and thinly slice the red onion.
Assemble the bowl by layering the cooked basmati rice, spiced chicken, fresh vegetables, and sliced avocado.
Drizzle the lemon-tahini yogurt sauce over the bowl and serve immediately.