Cook bacon in a skillet over medium heat until crispy. Drain on paper towels.

Season chicken with salt and pepper. Grill or pan-sear over medium heat for 6-7 minutes per side, until cooked through. Let rest, then slice.

In a large bowl, combine lettuce, tomatoes, avocado, red onion, sliced chicken, and crumbled bacon.

In a small bowl, whisk together mayonnaise and lemon juice. Drizzle over the salad and toss gently to combine.