Brush the bottom of an 8-inch square glass baking dish with the virgin olive oil. Place the prepared dish in the oven. Preheat oven to 350°F.
Remove the baking dish from the oven. Place the salmon, skin side down, in the baking dish. Brush the top of the salmon with the oil. Season the salmon with the kosher salt and Herbes de Provence.
Bake 20 minutes, or until the center is opaque and flakes easily when tested with a fork. (see tips below)
According to the USDA, the salmon's internal temperature should reach 145°F when tested in the thickest part with an instant-read thermometer. Many professionals feel this temperature is too high. Some, recommend an internal temp of 125°F. My personal preference is somewhere in between. If you are unsure, start with a lower internal temperature, check for opaqueness and flakiness, and then just try a small piece.
Leftover salmon can be stored in and airtight container and refrigerated for up to 2 days.