Start by combining all the Tzatziki ingredients in a bowl. Stir everything until it’s smooth and creamy, tasting as you go. Adjust the salt and lemon juice to find the perfect balance of tanginess. Once ready, refrigerate the sauce while you prepare the rest of your bowl. The flavors deepen as it chills, making it even more delicious.
Set a skillet over medium heat and add olive oil. Toss in shredded rotisserie chicken and season it with cumin, paprika, garlic powder, optional cayenne, salt, and pepper. Stir well, ensuring each strand of chicken is coated with spices. Cook for about 3-4 minutes until the chicken is warm and fragrant, then set it aside.
Divide the cooked brown rice evenly among four bowls. Add a generous layer of spiced chicken on top. Arrange the halved cherry tomatoes, Kalamata olives, red onions, and romaine lettuce around the chicken for a vibrant presentation. Sprinkle crumbled feta cheese across each bowl to tie the flavors together.
Finally, drizzle each bowl with the prepared Tzatziki sauce. You can either serve it on the side or mix it in for a creamy, tangy kick that complements the spices of the chicken and the freshness of the veggies. Serve immediately.