Toast fennel seeds, peppercorns, and mustard seeds in a nonstick skillet over medium heat until fragrant.
Transfer to a cutting board, add red chili flakes and crush with the back of a skillet.
Mix together with the salt, rosemary, and garlic.
Wrap the pork with the sopressata slices and tie together with kitchen string.
Lightly coat with olive oil and roll in spice mixture.
In an oven safe nonstick skillet, brown the pork on all sides over medium high heat. Transfer to a 400 °F oven and finish cooking, about 30 minutes, or until thermometer registers 155 degrees.
Rest the meat for 15 minutes before slicing and serving.
