Heat 1 tablespoon of olive oil in a skillet over medium heat. Season chicken breasts with salt and pepper. Cook for 6-7 minutes on each side until golden brown. Rest, chop into bite-sized pieces.

In a separate pan, cook bacon until crispy, about 5-7 minutes. Drain on paper towels and chop into small pieces.

In a mixing bowl, combine mayonnaise, sour cream, and ranch seasoning. Stir until smooth and creamy.

Add chopped chicken to the ranch dressing mixture. Finely chop and add red onion and celery. Fold in torn lettuce and diced tomatoes gently.

Fold in chopped bacon, reserving some bacon bits for topping if desired.

Slice hoagie rolls in half. Spoon chicken and ranch mixture into each half, packing gently. Top with reserved bacon and extra lettuce or tomatoes if desired.

Serve sandwiches immediately for best freshness and flavor.