Preheat oven to 350 degrees.
Line baking sheet with aluminum foil.
In a small bowl, combine garlic, basil, oregano, thyme, parsley, and sage. Set aside.
Generously season meat with salt and pepper.
In a large pan, heat oil until shimmery.
Add to pan, and cook on all sides until dark golden brown.
Transfer to baking sheet.
Generously coat with herb mix.
Place pats of butter on top of the pork.
Wrap in foil, bake until meat is 145 degrees internally at the widest, thickest part of the tenderloin (about 25 minutes.)
When pork has come to temperature, remove and let rest, tented with foil, for at least five minutes to lock in juices.
Slice against the grain and serve immediately.
To store leftovers, place in an airtight container and keep in refrigerator for up to three days.
To freeze leftovers, place in a plastic bag or wrap in plastic wrap and keep in freezer for up to three months.
To reheat, let thaw naturally in the refrigerator overnight, and bake at 350, wrapped in foil, until piping hot when ready to serve.