In a shallow dish, whisk together 30 ml of olive oil, 30 ml of lemon juice, oregano, thyme, garlic powder, salt, and pepper. Add chicken breasts and turn to coat. Marinate for at least 15 minutes at room temperature, or up to 4 hours in the refrigerator.

Preheat your grill to medium-high heat. Lightly oil the grill grates.

Grill chicken for 6-8 minutes per side, or until cooked through and internal temperature reaches 74 °C (74 °C). Let rest for 5 minutes before slicing.

While chicken rests, prepare the vinaigrette. In a small bowl, whisk together the remaining 15 ml olive oil, 15 ml lemon juice, Dijon mustard, honey, a pinch of salt, and pepper until emulsified.

In a large bowl, combine mixed greens, halved cherry tomatoes, and thinly sliced red onion. Add the sliced grilled chicken.

Drizzle the vinaigrette over the salad and toss gently to combine. Top with shaved Parmesan cheese just before serving.