Rice cauliflower in a food processor by dropping in florets and pulsing until cauliflower resembles grains of rice. Alternatively, buy "pre-riced" cauliflower fresh or frozen from Trader Joe's or Whole Foods.
In a large skillet over medium heat melt coconut oil, add cauliflower rice and cook until softened (about 4-5 minutes), add fresh cilantro, and salt. Stir together, remove from heat and reserve.
Mix together Za'atar, crushed garlic, salt, and olive oil. Spread over chicken. Grill until cooked through (I used a counter top grill and cooked for 12 minutes). Allow to cool, slice and set aside.
Quick pickled onions
Slice red onion into thin rounds, place in a colander or sieve. Pour boiling water over onions (this is to remove some of the pungency), then place in a small bowl or mason jar. Cover with vinegar, stir in salt and seeds (if using) allow to sit for 30 minutes or up to 5 days.
Place cauliflower rice in bottom of a bowl, top with sliced chicken, pickled onions, diced cucumber, tomato, watercress, and radish. Drizzle with tahini dressing.
For a vegan version eliminate the chicken and replace with tempeh