Prepare the ingredients as instructed above, rinsing the rice and chopping all vegetables before cooking.
Cook the rice according to package directions. Once cooked, fluff with a fork and keep warm, covered.
Make the shawarma marinade by mixing garlic, coriander, cumin, cardamom, smoked paprika, salt, black pepper, lemon juice, and olive oil in a bowl until combined.
Add the chicken to the marinade and toss to coat evenly. Allow the chicken to marinate while preparing the remaining components.
Prepare the garlic sauce by blending garlic, olive oil, salt, black pepper, and lemon juice until smooth and fluffy. (Optional: boil the garlic in water for 5 minutes first for a milder flavor, then drain before blending.)
Heat a grill or skillet over medium heat. Grill the marinated chicken on both sides until grill-marked and the internal temperature reaches 160°F (71°C).
Remove the chicken from heat and let it rest for 5 minutes, then slice into strips.
Assemble the bowls by portioning the rice and topping with lettuce, cucumber, tomato, red onion, feta, chicken, and pickles. Drizzle with garlic sauce.
Mix together the milk, ground cinnamon, and protein powder until well combined.
Serve the shawarma bowls with cinnamon milk.