Cook the bacon. Add bacon to a cold skillet and set over medium heat.
Cook until crispy, about 8–10 minutes, turning as needed. Transfer to a paper towel–lined plate. Reserve 1–2 tablespoons of bacon fat in the pan.
Season the chicken. Pat chicken dry and cut into bite-size strips or cubes.
Toss with garlic powder, onion powder, smoked paprika, dried dill, black pepper, and salt.
Sear the chicken. Heat the reserved bacon fat over medium-high. Add chicken in a single layer. Cook 5–7 minutes, stirring once or twice, until browned and cooked through.
If the pan gets crowded, cook in batches for the best sear.
Chop the bacon. While the chicken cooks, chop the bacon into small pieces.
Toss with ranch. Reduce heat to low. Return all chicken to the pan and add ranch dressing. Stir until the chicken is evenly coated and glossy.
If you like a brighter flavor, splash in lemon juice.
Add the bacon and cheese. Stir in chopped bacon and half the cheese. Warm until the cheese melts into the sauce and everything clings together. Taste and adjust salt or ranch as needed.
Prep the shells. Separate lettuce leaves, rinse, and pat completely dry.
Choose sturdy leaves about hand-length for easy filling.
Assemble. Spoon the chicken-bacon-ranch mixture into lettuce shells. Top with remaining cheese and your favorite add-ons like avocado, green onions, or jalapeños.
Serve right away. These taste best when the filling is hot and the lettuce is crisp.