In a large skillet, heat 1 tablespoon of olive oil over medium heat.

Add 1 pound of diced chicken breasts to the skillet, seasoning generously with salt and pepper. Cook the chicken for about 8-10 minutes, stirring occasionally, until it turns golden brown and is no longer pink in the center.

While the chicken is cooking, heat a separate skillet over medium heat and place 4 slices of bacon in it. Cook the bacon for approximately 6-8 minutes until crispy, flipping occasionally. Transfer the bacon to a paper towel-lined plate to drain excess grease, then chop it into small pieces.

In the skillet with the cooked chicken, add the chopped bacon and ½ cup of ranch dressing. Stir well to combine for about 2-3 minutes.

Slice 4 sandwich buns or rolls in half, and if desired, toast them lightly until golden brown.

On each bottom half of the toasted buns, layer 1 cup of shredded lettuce and ½ cup of diced tomatoes. Spoon the warm chicken and bacon mixture generously over the veggies.

Top each sandwich with the other half of the bun, pressing down gently to secure the fillings. Serve immediately.