The chicken needs to marinate before anything else happens. In a blender or food processor, combine all fresh herbs, dry spices, garlic, olive oil, and 2–3 tablespoons of the Greek yogurt. Blend to a fragrant, thick paste. In a large bowl, combine the remaining yogurt, lemon juice, and lemon zest, then fold in the herb-spice paste until fully incorporated. Cut the chicken thighs into 1.5-inch pieces, add to the marinade, and mix thoroughly by hand. Cover and refrigerate for a minimum of 2 hours — overnight is the target and produces noticeably better results. The full technique and marinade detail is in the Greek Chicken Souvlaki recipe.

Slice the red onions into thick rings — thick enough to hold their shape and provide genuine texture in the bowl rather than collapsing into thin slivers. In a heatproof jar or bowl, combine the boiling water, vinegar, sugar, salt, coriander seeds, and black peppercorns, stirring until the sugar and salt are completely dissolved. Add the onion rings and press them down gently until fully submerged. The onions need a minimum of 30 minutes in the pickling liquid before they are ready — they will turn from sharp and raw-tasting to sweet, tangy, and bright with a beautiful pink-purple color. They continue to improve over 24 hours in the refrigerator, making them an ideal make-ahead component. For this bowl they are not a condiment — they are a full flavor component, and their sharp-sweet acidity is what cuts through the richness of the tzatziki and avocado.

Grate the cucumber and squeeze with maximum force — this is the step that determines whether the tzatziki is thick and spoonable or thin and watery, and there is no correcting it after the fact. Combine the squeezed cucumber with Greek yogurt, minced garlic, lemon juice, olive oil, fresh dill, fresh mint, and salt. Fold gently — do not whisk or beat. Cover and refrigerate for at least 20 minutes. The full technique is in the Tzatziki recipe. For this bowl the tzatziki is served in a generous spoonful on one side — it is both a sauce and a cooling contrast element, so make it thick enough to hold its shape when spooned.

Warm the olive oil in a medium saucepan over medium-low heat. Add the minced garlic and cook for 60 seconds, then add all four spices and bloom for 30–45 seconds, stirring constantly, until intensely fragrant. Add the tomato paste and stir for another 30 seconds to caramelize it slightly in the spiced oil. Pour in the chicken broth, season with salt and pepper, and bring to a full boil. Remove from heat, pour in the couscous, stir once, cover tightly, and leave undisturbed for 5 minutes. Fluff with a fork only — never a spoon. The full technique and notes are at Moroccan-Style Tomato Couscous. Keep covered and warm until assembly.

Cut the tomatoes into large, chunky cubes — not fine dice. The pieces should be substantial enough to be scooped up with the chicken and couscous in a single forkful. Cut the unpeeled cucumber into the same size. Combine in a bowl, season generously with salt and freshly ground black pepper, and drizzle with the olive oil. Toss briefly and leave to rest — the salt will draw a small amount of juice from the tomatoes that mixes with the olive oil into a simple, natural dressing. Prepare the avocado last, immediately before assembly, to prevent browning. Halve, pit, and cut the flesh into cube-sized chunks while still in the skin, then scoop out carefully with a large spoon. Season with salt and black pepper directly.

Take the marinated chicken from the refrigerator while you heat your cooking surface — grill, grill pan, cast iron, or carbon steel. Thread the pieces onto skewers without over-packing. The surface must be screaming hot before the chicken goes on — 3–4 minutes of preheating minimum. Do not wipe the marinade from the chicken pieces; the yogurt coating is what creates the char and crust. Cook the first side undisturbed for 3–4 minutes until deep golden-brown, flip, and cook the second side for another 3–4 minutes. If cooking in a pan, work in batches — an overcrowded pan drops temperature and steams rather than sears. Rest all cooked skewers for 5 minutes before assembling.

Work from the reference image: add a generous portion of Moroccan tomato couscous to one side of each bowl as the grain base. Lean 2–3 skewers of chicken souvlaki across the center of the bowl, resting against the couscous. Spoon a generous mound of tzatziki on the opposite side of the chicken — it should look abundant, not like a condiment drizzle. Add the tomato-cucumber salad in a section adjacent to the tzatziki. Place the avocado cubes in their own section alongside the couscous. Lay a portion of the pickled red onion rings in the remaining space. Finish every bowl with a very generous scattering of roughly chopped fresh parsley or cilantro over the entire surface — do not be subtle with it. The herbs are as much a visual element as a flavor one in this bowl.