Blend the cilantro, olive oil, lime juice, garlic, red pepper flakes, and salt in a blender until smooth; pour into a large resealable plastic bag. Add the pork tenderloin to the bag and manipulate to assure it's covered with the marinade. Remove as much air from the bag as possible before sealing. Marinate in refrigerator 8 hours to overnight.
Stir the chicken broth and lemon juice together in the bottom of a pressure cooker. Lay the tenderloin into the liquid in the slow cooker. Pour the remaining marinade from the bag over the tenderloin.
Seal and lock pressure cooker and cook over high heat to build pressure until the indicator sounds. Reduce heat to medium and cook for 25 minutes. Remove from heat and let stand for 5 minutes. Run under cold water to help release the pressure before unsealing the lid. Slice the tenderloin into medallions to serve.