Preheat the grill to medium-high heat.

In a bowl, toss the zucchini, bell peppers, and onion with olive oil, salt, and pepper.

Place the vegetables on the grill and cook for about 5-7 minutes, turning occasionally, until tender and slightly charred.

In a large mixing bowl, combine the mixed salad greens, cherry tomatoes, and cucumber.

Add the grilled vegetables to the salad bowl.

Crumble the feta cheese over the top.

In a small bowl, whisk together the balsamic vinegar, olive oil, honey, dijon mustard, salt, and pepper.

Drizzle the dressing over the salad and toss gently to combine.

Transfer the salad to a serving platter and enjoy immediately.