Pour the chicken broth into the skillet and scrape up any browned bits.
Allow the chicken broth to simmer for about 2 to 3 minutes.
Reduce the heat to low and stir in the heavy cream, Dijon mustard, and thyme. Let the sauce simmer gently for about 3 to 4 minutes until thick.
Return the seared pork tenderloin to the skillet and spoon the sauce over it. Cover the skillet and let it simmer for about 5 to 7 minutes.
Remove the pork from the skillet, let it rest for a few minutes, then slice into medallions and pour the sauce over the top. Garnish with fresh parsley.
Notes
Store leftovers in an airtight container for up to 3-4 days. Reheat gently in a skillet over low heat.