Make the quick dressing: In a small bowl, whisk together lemon zest, lemon juice, garlic, Dijon, honey, 2 tablespoons olive oil, salt, and pepper. Add red pepper flakes if you like a little heat.
Set aside.
Sauté the veggies: Heat a large skillet over medium-high. Add a drizzle of olive oil. Cook the red onion for 2 minutes until slightly softened.
Add zucchini and corn, and cook 3–4 minutes until crisp-tender with a bit of char. Season with a pinch of salt.
Warm the chicken: Push the veggies to the side of the skillet. Add the chicken to the open space with a small splash of water or a squeeze of lemon to keep it moist.
Warm for 1–2 minutes.
Add tomatoes and herbs: Toss in cherry tomatoes and half of the chopped herbs. Cook 1 minute just to take the chill off the tomatoes without breaking them down.
Dress it up: Take the skillet off the heat. Pour over about two-thirds of the dressing and toss gently so everything is glossy but not soggy.
Taste and adjust salt, pepper, or lemon.
Choose your base: For a bowl, spoon the mixture over warm grains. For a salad, pile it onto mixed greens. For wraps, layer into warm tortillas or pitas.
Finish and serve: Top with avocado and cheese if using.
Sprinkle remaining herbs and drizzle the rest of the dressing as needed. Serve immediately.