Remove the chicken breast from the fridge and pat dry with paper towels. Use a sharp knife to butterfly the breast — place your hand on the breast and slice through it starting at the thickest part to slice it in half horizontally. Season with kosher salt, garlic powder, oregano, pepper. Set aside while you heat the grill and cook the bacon.
Heat a grill for medium high two zone cooking. We like to cook the bacon on a cast iron skillet on the grill. Cook the bacon over direct heat for 8 to 10 minutes until crisped. Move the paper towels to drain. While the bacon cooks, thinly slice the tomato and red onion. lay the tomato slices out into a single layer and season generously with kosher salt.
Cook the chicken over direct heat with the grill lid closed, until the first side begins to caramelize, about 4 minutes. Flip the chicken breast and cook 4 to 5 minutes more until it reach 160 degrees F. Once the chicken is off the grill, toast the bread briefly — about a minute per side.
Build the sandwiches by swiping two slices of bread with mayo and topping with a piece or two with lettuce. Add a piece of chicken, two slices of tomatoes, onion slices and season with more salt and pepper. Add the bacon slices and top with an additional slice of berad.