Pat the pork tenderloin dry and season with salt and pepper.
Heat oil in a cast-iron skillet over medium-high heat. Sear the pork for 2-3 minutes per side until golden brown.
Lower the heat and add butter and minced garlic, cooking until fragrant.
Pour in chicken broth, Dijon mustard, and lemon juice. Stir to combine.
Return the pork to the pan and let it simmer in the sauce for 5-7 minutes, until it reaches an internal temperature of 145°F (63°C).
Let the pork rest for 5 minutes before slicing. Serve with extra garlic sauce drizzled on top.