Season the two pork tenderloins with some salt, pepper, dried oregano, garlic powder, dried basil, dried thyme, and paprika. Use your hands to rub the seasoning around so both tenderloins are evenly coated.
Heat up a large cast iron pan until smoking, then add a tablespoon of olive oil. Lay the pork chops down and sear them for five minutes on the first side, then 3-4 minutes on the other sides. Make sure not to touch them while they're searing, however tempted you may be, so you get the best color.
When done, set the seared tenderloins aside and start the gravy. Add some more olive oil to the cast iron and add the mushrooms, onions, and garlic. Saute for 7-10 minutes until softened. Season with salt, pepper, and basil.
Add the mustard, brown sugar, butter, and flour. Let the sauce thicken, then add the wine and cook for another 3 minutes. Add the stock/water and stir, letting it come to a mild simmer.
Nestle the tenderloins back into the gravy and cover with a lid, letting the tenderloins sit in the gravy until they reach 145-150ºF in the center (use a meat thermometer). To serve, slice the tenderloins and spoon gravy over the slices. Enjoy!
