Cook and crumble the bacon, grill or shred the chicken, and slice all vegetables. Set aside.
In a small bowl or jar, whisk together the lemon juice, olive oil, Dijon mustard, honey (if using), garlic, salt, and pepper until emulsified.
In a large salad bowl or platter, layer the mixed greens with chicken, bacon, avocado, tomatoes, red onion, and cucumber.
Drizzle the lemon vinaigrette over the salad. Toss gently to coat everything evenly.
Serve right away for the freshest flavor and best texture. Add extra lemon wedges or a sprinkle of feta if desired.