Cook the bacon: Place bacon in a cold skillet and cook over medium heat until crisp, 8–10 minutes. Transfer to a paper towel–lined plate.
Crumble when cool. Reserve a teaspoon of bacon fat for extra flavor in the dressing if you like.
Cook the chicken (skip if using pre-cooked): Pat chicken dry. Season with salt, pepper, smoked paprika, and garlic powder.
Heat oil in a skillet over medium-high. Sear 5–7 minutes per side for breasts (4–6 for thighs), until cooked through. Let rest 5 minutes, then slice or cube.
Make the dressing: In a small bowl, whisk mayo, sour cream (or yogurt), Dijon, lemon juice, garlic, and olive oil.
Stir in a pinch of salt and pepper. Add a splash of water to thin until pourable. For extra richness, whisk in 1 teaspoon warm bacon fat.
Taste and adjust acid or salt.
Prep the salad base: Add chopped romaine to a large bowl. Top with tomatoes, avocado, and red onion. Sprinkle cheese if using.
Add the proteins: Pile on the sliced chicken and crumbled bacon.
Toss and serve: Drizzle with dressing and toss gently to coat.
Serve immediately, with extra black pepper or a squeeze of lemon on top.