In a cold skillet, lay the bacon slices. Turn heat to medium and fry until the fat renders and the bacon is crispy and glossy. Remove and drain on paper towels.

Season chicken with salt and pepper. In the same skillet (remove excess grease first), sear chicken over medium-high heat for 5-6 minutes per side until the internal temperature reaches 165°F (74°C). The texture should be fibrous and juicy.

Wipe the skillet and add butter. Toast sourdough slices until an uneven golden crust forms with natural crumbs.

Mix mayo and lemon juice. Spread on toast. Layer lettuce, hot chicken, cheese (to allow melting), bacon, and tomatoes. Close the sandwich and press gently.