Rinse and toast the quinoa: Place 1/2 cup dry quinoa in a fine-mesh sieve and rinse under cold water until the water runs clear (this removes the bitter saponin coating). Drain. Heat a small saucepan over medium heat and add the drained quinoa; toast, stirring, for 60–90 seconds until it smells nutty — toasting deepens the quinoa’s flavor and keeps the grains distinct when cooked.

Cook the quinoa: Add 1 cup (240 ml) water and a pinch (about 1/4 tsp) of salt to the saucepan, bring to a gentle boil, then reduce to low, cover and simmer for 12–15 minutes until the water is absorbed. Remove from heat and let rest covered for 5 minutes; then fluff with a fork. Resting lets trapped steam finish cooking the quinoa and gives a fluffier texture.

Season the chicken: Pat the 12 oz chicken breasts dry with paper towels (dry surface = better sear). Season both sides with 1/2 tsp kosher salt, 1/4 tsp freshly ground black pepper and, if using, 1/4 tsp smoked paprika. Light seasoning highlights the chicken’s natural flavor and smoked paprika adds a warm, savory note without overpowering the dressing.

Preheat your grill or grill pan: Heat a grill or heavy grill pan to medium-high (about 400°F/200°C) and oil the grates or pan very lightly using a folded paper towel dipped in neutral oil — this prevents sticking without adding measured oil to the recipe. A hot surface gives immediate contact heat that creates a caramelized crust and locks in juices.

Grill the chicken: Place the chicken on the hot grill and cook undisturbed for 4–6 minutes per side (depending on thickness) until well-marked and an instant-read thermometer inserted into the thickest part reads 160–162°F (71–72°C). Why: cooking to this temperature then resting ensures safety and a juicy result; carryover heat will raise the internal temp a few degrees while resting to reach 165°F.

Rest and slice the chicken: Transfer the chicken to a cutting board and tent loosely with foil for 5–7 minutes. Resting redistributes juices so the meat stays moist when sliced. Then slice the breast thinly against the grain for tender bites.

Warm the roasted vegetables and assemble base: If your mixed roasted vegetables are chilled, warm them briefly in a skillet over medium heat just until hot (about 2–3 minutes) — quick reheating preserves their texture. Place 2 cups baby spinach in a large bowl, add the warm roasted vegetables and 1 cup of the cooked quinoa; toss to combine. Using warm components (quinoa, vegetables) helps wilt the spinach gently and meld flavors.

Make the lemon‑tahini dressing: In a small bowl whisk together 3 tbsp tahini, 2 tbsp extra‑virgin olive oil, juice of 1 lemon (about 2 tbsp), 1 minced small garlic clove, 1 tbsp chopped parsley or cilantro, and 1/4–1/2 tsp kosher salt and a few grinds of black pepper to taste. If the dressing is very thick, whisk in 1–2 tbsp warm water, a teaspoon at a time, until it reaches a glossy, pourable consistency. Whisking and thinning unlocks tahini’s oils and gives the dressing a silky texture that coats the salad evenly.

Assemble the salad: Add the remaining cooked quinoa (if not already added), sliced grilled chicken and sliced avocado on top of the spinach/veggie base. Drizzle 2/3–3/4 of the lemon‑tahini dressing over the salad and toss gently to combine — save a little dressing to finish the plate. Tasting as you go helps balance acidity and salt.

Finish and serve: Divide the salad between two plates or shallow bowls, drizzle the remaining dressing over each portion, and finish with an extra pinch of flaky sea salt and a grind of black pepper. Serve immediately so the avocado stays glossy and the chicken stays warm — this contrast of warm chicken and quinoa with cool spinach and avocado is central to the dish’s appeal.