Quinoa and chicken:
1/2 cup quinoa
2 large skinless, boneless chicken breasts (about 18 oz.)
2 Tbsp. extra-virgin olive oil
Freshly ground black pepper
Dressing and assembly:
1 cup vegan or regular mayonnaise
2 Tbsp. fresh lime juice
2 tsp. culinary-grade matcha
1 1/2 tsp. Dijon mustard
1/2 tsp. agave nectar
2 garlic cloves
1 1/2 tsp. kosher salt, plus more
1/2 cup basil leaves
1/4 cup parsley leaves with tender stems
12 cups baby greens (such as kale, spinach, and/or arugula)
2 cups cherry tomatoes, halved
4 Persian cucumbers, cut into 1" pieces (about 2 cups)
2 avocado, cut into 3/4" pieces
1 1/3 cups crumbled feta
Quinoa and chicken:
Bring a small pot of water to a boil. Add quinoa, return to a boil, and cook until tender, 15–20 minutes. Drain, return quinoa to warm pot, and fluff with a fork to release some of the steam. Season with salt; cover to keep warm until ready to serve.
Meanwhile, prepare a grill for medium-high heat. (Or heat a cast-iron grill pan or medium skillet over medium-high.) Rub chicken on all sides with oil and season with salt and pepper. Grill (or sear) chicken, turning halfway through, until just cooked through, 12–15 minutes. Transfer chicken to a cutting board and let rest 5 minutes, then cut into 1/2" pieces.
Dressing and assembly:
Purée mayonnaise, lime juice, matcha, mustard, agave, garlic, and 1 1/2 tsp. salt in a food processor until smooth. Add basil and parsley and pulse until incorporated.
Toss quinoa, chicken, greens, tomatoes, and cucumbers in a large bowl to combine. Add 1/2 cup dressing and toss to coat; season with salt.
Divide salad among bowls and top with avocado and feta. Serve remaining dressing alongside.