Preheat your grill or grill pan to medium-high heat. In a large bowl, toss the zucchini planks with 2 tablespoons of olive oil, 1/2 teaspoon salt, and 1/4 teaspoon black pepper, ensuring they are evenly coated.

Place the zucchini planks on the hot grill. Grill for 2-3 minutes per side, until tender with visible grill marks. Remove from grill and let cool slightly. Once cool enough to handle, cut the grilled zucchini planks into 1-inch pieces.

While the zucchini cools, prepare the vinaigrette. In a small bowl or jar, whisk together the extra virgin olive oil, fresh lemon juice, Dijon mustard, minced garlic, chopped oregano, 1/4 teaspoon salt, and a pinch of black pepper until well combined.

In a large mixing bowl, combine the cooled grilled zucchini pieces, halved cherry tomatoes, thinly sliced red onion, crumbled feta cheese, chopped fresh mint, and chopped fresh parsley.

Pour the lemon-herb vinaigrette over the salad ingredients. Toss gently to coat everything evenly. Serve immediately, perhaps over a bed of mixed greens if desired.