Prep the chicken: In a bowl, mix 2 tablespoons olive oil, zest of 1 lemon, juice of 1/2 lemon, 2 minced garlic cloves, 1.5 teaspoons cumin, 1 teaspoon smoked paprika, 1 teaspoon dried oregano, 1 teaspoon salt, and 1/2 teaspoon black pepper. Add chicken and toss to coat.
Marinate at least 20 minutes (up to 24 hours in the fridge).
Cook the grains: Prepare rice, quinoa, or couscous according to package directions. Fluff and season with a pinch of salt and a drizzle of olive oil. Keep warm or cool for a room-temp bowl.
Make the lemon tahini: In a small bowl, whisk 1/2 cup tahini, juice of 1 lemon, 1 teaspoon lemon zest, 1 small grated garlic clove, 1–2 tablespoons olive oil, 1–2 teaspoons honey or maple syrup, and 1/2 teaspoon salt.
Whisk in warm water, 1 tablespoon at a time, until smooth and pourable. Taste and adjust acidity and salt.
Chop the vegetables: Halve cherry tomatoes, dice cucumber, thinly slice red onion, and roughly chop parsley and/or mint. If using olives and feta, keep them ready.
Cook the chicken: Grill over medium-high heat 5–7 minutes per side (thighs) or 4–6 minutes per side (breasts), until the thickest part reaches 165°F/74°C.
Alternatively, sear in a hot skillet with a little oil, or roast at 425°F/220°C for 18–22 minutes. Rest 5 minutes, then slice.
Assemble the bowls: Add a scoop of grains to each bowl. Top with greens, tomatoes, cucumber, and onion.
Add sliced chicken, a handful of herbs, and any extras like olives or feta. Spoon over lemon tahini and finish with a squeeze of lemon and a crack of black pepper.
Serve: Drizzle a little more olive oil if you like. For crunch, sprinkle toasted pine nuts or a pinch of sumac.