Season the chicken. Pat the chicken dry. Rub with olive oil, salt, garlic powder, paprika, and pepper.
Cook the chicken. Grill over medium-high heat 5–7 minutes per side, or pan-sear in a hot skillet with a little oil until the internal temperature reaches 165°F (74°C).
Rest 5 minutes, then slice.
Toast the nuts. Add almonds or pecans to a dry skillet over medium heat. Stir until fragrant and lightly golden, 3–4 minutes. Cool.
Make the dressing. Whisk olive oil, honey, lemon juice, Dijon, salt, and pepper until smooth.
Taste and adjust acidity or sweetness as needed.
Prep the salad base. In a large bowl, add the spring mix, strawberries, red onion, herbs, and avocado if using.
Dress lightly. Drizzle about half the dressing over the greens and toss gently until just coated.
Add protein and crunch. Top with sliced chicken, toasted nuts, and cheese. Spoon on a little more dressing to taste.
Serve. Plate immediately so the greens stay crisp. Finish with a pinch of salt and a crack of pepper for brightness.