Preheat your oven to 400°F (200°C).
In a small bowl, combine olive oil, herbes de Provence, minced garlic, salt, and pepper. Rub this mixture all over the pork tenderloin.
Heat a large oven-safe skillet over medium-high heat. Sear the pork on all sides until golden brown, about 3-4 minutes per side.
Transfer the skillet with the pork to the oven and roast for 20-25 minutes, or until an internal temperature of 145°F (63°C) is reached. Remove pork and let it rest.
While the pork roasts, soak the dried porcini mushrooms in boiling water for 15 minutes, then drain and reserve the soaking liquid.
In a medium saucepan, melt a tablespoon of olive oil over medium heat. Add sliced shallots and cook until translucent, about 3 minutes.
Add the soaked porcini mushrooms and cook for another 2 minutes.
Deglaze the pan with the cognac, letting it simmer and reduce by half.
Add the reserved porcini soaking liquid (avoiding sediment) and lemon juice. Bring to a gentle simmer.
Stir in the honey and heavy cream, simmering until the sauce thickens slightly, about 5 minutes.
Remove the sauce from heat and whisk in the chilled butter cubes one at a time to enrich and thicken the sauce.
Slice the rested pork tenderloin and serve topped with the porcini cognac cream sauce.