In a small skillet or frying pan, cook bacon strips on medium high heat until crispy. Turn and cook both sides, then remove from skillet or pan and set on paper towel to drain excess fat and allow to cool for assembling the club sandwich.
In a small to medium sized skillet or frying pan, bring olive oil to medium high heat and pan sear the chicken breast (either pre-cut chicken tenders, cut into strips yourself, or cook a whole chicken breast and cut once done). Season with salt, pepper, onion powder, and paprika. When cooked through, remove from the pan and set aside for assembling the sandwich (cut the chicken pieces into strips, if needed).
While the chicken is cooking, toast the bread pieces and spread mayonnaise on one side of two pieces and both sides of what will be the center piece of bread. Stack the sandwich beginning with the first piece of toasted bread, add bacon, red onion, and lettuce.
Place the center piece of bread on the stacked sandwich, then add avocado, tomato, and chicken. Top it off with the last piece of bread and hold the sandwich in place with either one or two long skewers.
*Add cheese slices of your favorite variety anywhere in the stacked Chicken Club Sandwich!