1.Add pancetta to large skillet on MEDIUM. Cook, stirring often, about 10 min or until almost crispy.
2.Season shrimp with salt and pepper. Raise heat to MEDIUM-HIGH; add shrimp and green onions. Cook, stirring, 2 min. Add stock; bring to simmer. Cook about 2 min until internal temp of shrimp reaches 130 (check by inserting thermometer into thickest part of shrimp). Remove pan from heat.
3.Add parsley and butter; stir until butter melts.