Prepare the chicken and marinade: Pat the 640 g chicken breasts dry with paper towels — dryness helps the marinade stick and promotes browning. Place chicken between two sheets of plastic and lightly pound to an even thickness (about 1/2–3/4 inch) so they cook evenly. Why: uniform thickness prevents thin edges from drying out while thicker centers finish cooking.

Make the marinade: In a bowl whisk together 2 tbsp (30 ml) lemon juice, 2 tbsp (30 ml) olive oil, the minced garlic (about 2 cloves), 2 tbsp chopped parsley, 1 tbsp chopped mint, 1/2 tsp kosher salt and 1/4 tsp cracked black pepper. Reserve the remaining lemon juice, olive oil and herbs for the dressing. Why: the acid (lemon) brightens flavor and, for a short marinade time, helps flavor the surface without making the meat mealy; olive oil carries aromatics and protects the surface while grilling.

Marinate briefly: Place the chicken in a shallow dish or zip‑top bag and pour the marinade over. Marinate at room temperature for 15–30 minutes or refrigerate up to 2 hours. Why: because the chicken is cut and pounded thin, it only needs a short time to pick up flavor — longer (over 2 hours) with citrus can begin to firm the surface.

Prepare the quinoa salad base: While the chicken marinates, place the 600 g cooked quinoa in a large mixing bowl and fluff with a fork to separate grains. Why: fluffing prevents clumping and lets the dressing coat each grain.

Warm the vegetables (optional step for texture): Heat a medium skillet over medium heat with a drizzle (1 tsp) of olive oil. Add the blanched asparagus tips (300 g) and the peas (200 g) just to warm and re‑brighten the vegetables — 1–2 minutes: you want them crisp‑tender, not mushy. Why: warming the veggies slightly allows them to marry with the warm quinoa so flavors meld; quick heating revives color and preserves texture.

Combine salad ingredients: Add the blanched asparagus and peas to the quinoa along with the halved cherry tomatoes (24), remaining 2 tbsp chopped parsley and 3 tbsp chopped mint (reserve a tablespoon for garnish). Why: adding herbs and tomatoes at this point ensures fresh aromatic lift and a juicy counterpoint to the nutty quinoa.

Make the lemon‑herb dressing: Whisk together the reserved 2 tbsp lemon juice, 2 tbsp olive oil, a pinch of salt and cracked pepper and 1 tbsp finely chopped mint. Taste and adjust — the dressing should be bright and balanced (noticeable lemon, but not harsh). Why: finishing dressing at the end keeps herbs tasting bright and the acid from cooking away.

Dress the quinoa salad: Pour the dressing over the warm quinoa and vegetables and toss gently to combine. Taste and correct with salt, pepper or an extra squeeze of lemon if needed. Why: warm grains absorb dressing better than cold; tossing gently keeps asparagus and tomatoes intact.

Preheat your grill or grill pan: Heat a gas or charcoal grill to medium‑high (about 400–450°F / 200–230°C) or heat a heavy grill pan over medium‑high on the stovetop until just smoking. Why: a hot surface creates Maillard browning — the flavorful, caramelized crust — quickly so the interior remains juicy.

Grill the chicken: Remove chicken from the marinade and let excess drip off (discard used marinade). Grill chicken 4–6 minutes per side (depending on thickness) until well marked and an instant‑read thermometer reads 165°F (74°C) in the thickest part. Why: grilling time yields a golden‑charred exterior and safe, juicy interior; thermometer prevents overcooking.

Rest and slice the chicken: Transfer chicken to a cutting board and rest for 5 minutes. Slice thinly across the grain. Why: resting lets juices redistribute so slices stay moist; cutting across the grain shortens muscle fibers for a more tender bite.

Assemble and finish: Divide the quinoa salad among four plates or a communal platter. Fan the sliced grilled chicken over each portion. Spoon any resting juices into a small bowl and drizzle lightly over chicken (for extra flavor). Garnish with reserved chopped herbs, cracked black pepper and optional toasted almonds or lemon wedges. Why: plating warm grain first keeps the chicken from cooling too quickly and finishing with fresh herbs and a squeeze of lemon keeps the dish bright and restaurant‑polished.