1. Preheat oven to 325°F. Cut each tenderloin into 6 2-inch slices and pound to 3/4-inch thickness. Season both sides with salt and pepper.
2. Melt butter with oil in a large skillet over medium-high heat. Working in batches, add pork and cook until lightly browned, about 1 minute per side. Place on a rimmed baking sheet and transfer to oven. Cook until internal temperature is 145°F, 18 to 20 minutes.
3. Pour off fat from skillet, increase heat to high and add wine. Boil rapidly, scraping up browned bits, until reduced to 1 Tbsp., about 2 minutes. Add broth and cream. Bring to a simmer over medium-high heat and cook, stirring, until thickened, 10 to 12 minutes. Remove from heat and stir in mustard and cilantro. Taste and season with salt and pepper. Serve sauce over medallions.