Preheat oven to 375ºF.
Sauté onions and garlic with butter until slightly brown. Add mushrooms and sweat until cooked.
Add fresh thyme, salt, and pepper to taste.
Deglaze with little bit of white wine and set aside to cool.
Use a sharp knife and butterfly the pork loin.
Season the pork loin with salt and pepper.
Spread the mushroom mixture on the butterflied pork loin. Roll up the pork loin.
Make a bacon weave.
Place pork loin on the bacon weave and roll it up somewhat tightly.
Cook at 375ºF oven for 30-45 minutes or until internal temperature reaches 160ºF.
Let meat rest for 10 minutes before cutting into it.
Cut and enjoy.