Preheat oven to 425 degrees F.
Finely zest the lemons. Put the zest in a small bowl and add the salt. If you have a mortar and pestle this is the time to pull it out, otherwise the end of a rolling pin works just as well. Using the end of the rolling pin gently work the lemon salt and zest together. It should be a rough paste texture. Add some freshly ground pepper and 1 tablespoon of olive oil. Stir to blend ingredients together.Rub the lemon salt mixture all over the pork. This is best done using your (washed and cleaned) hands.
In a large oven proof sauté pan, heat the remaining tablespoon of olive oil until it shimmers, but doesn’t smoke. Add tenderloins to pan and sear tenderloins on all sides, using tongs to turn them around in the pan. This should take about 5 minutes total. If you don’t have room in your pan for both tenderloins, sear one at a time.
Once both tenderloins are nicely browned on all sides, place pan in oven and cook until a meat thermometer reads 155 degrees F. Depending on your oven, this should take about 15-20 minutes.
Remove pork from pan, let it rest on a separate platter and cover with foil.
While the pork rests, make the gravy. In the same pan you cooked the pork, melt the butter then add broth and wine. Bring to a boil, scrapping up all the goodies from the bottom of the pan. When the liquid is reduced by about half, stir in the cream and taste to adjust seasonings. Simmer until it thickens up, about 3-5 minutes. I find that because you use a bunch of salt to cook the pork, the gravy doesn't need any additional salt. If you want the sauce creamier, add another tablespoon or two of cream.
Slice the pork, and spoon the gravy over it. Serve immediately.