Wash and dry produce.

Trim and discard root end from lettuce; chop leaves into bite-size pieces. Quarter lemon.

Heat a drizzle of oil in a large pan over medium-high heat. Add prosciutto in a single layer; sear until browned and crispy, 2-3 minutes per side (work in batches for 4 servings). TIP: If prosciutto starts to crisp too quickly, reduce heat to medium.

Turn off heat; transfer to a paper-towel-lined plate. Reserve oil in pan (you’ll use it to cook chicken in the next step).

Pat chicken* dry with paper towels; season all over with salt and pepper.

Heat pan with reserved oil over medium-high heat. (TIP: Add another drizzle of oil if pan seems dry.) Add chicken; cook until browned and cooked through, 5-7 minutes per side.

In a large bowl, toss lettuce with dressing, half the Parmesan, a drizzle of olive oil, a squeeze of lemon juice, salt, and pepper (large drizzle of olive oil and big squeeze of lemon juice for 4 servings). Crumble half the prosciutto into bowl; toss to combine. Taste and season with additional lemon juice, salt, and pepper if desired.

Thinly slice chicken crosswise.

Divide salad between shallow bowls; top with chicken and remaining Parmesan. Crumble remaining prosciutto over top. Serve.