In a large bowl, combine boiling water, kosher salt, and brown sugar until dissolved. Add cold water, then submerge the pork tenderloin completely. Allow it to brine for 30 to 60 minutes for maximum juiciness.

Preheat your oven to 400°F (200°C) to prepare for roasting.

In a small bowl, mix together smoked paprika, garlic powder, onion powder, black pepper, dried thyme, cayenne, and remaining kosher salt. Rub this mixture all over the tenderloin.

Heat olive oil in an oven-safe skillet over medium-high heat. Sear the pork tenderloin for 2-3 minutes on each side until it develops a golden crust.

Add 1 tbsp of water to the skillet, then transfer the whole pan to the preheated oven. Roast for 15-25 minutes or until the internal temperature reaches 145°F (63°C).

Let the pork rest for about 10 minutes before slicing.

In the same skillet, melt the butter over medium heat until it turns light caramel color. Add chicken broth, Dijon mustard, maple syrup, apple cider vinegar, and soy sauce. Bring it to a boil, then reduce the heat and simmer for 5 minutes.

Mix cornstarch with cold water, add it to the glaze, and let it simmer for an additional 30-60 seconds until thickened. Stir in the juices from the resting pork, then strain and season with salt and pepper.

Slice the pork into 1/2-inch medallions and spoon the glaze over each piece.