Method:
Preheat oven to 350°F. Sprinkle half the shallot in a baking dish large enough to hold all of the fish in a single layer. Rub each fillet all over with a teaspoon of olive oil. Lightly season one side of each fillet with cooking salt and pepper. Place fillets on top of shallots in the baking dish, seasoned side down, and sprinkle with remaining shallot. Bake 12 to 15 minutes or until flesh is opaque and flakes with a fork.
While fish bakes, prepare the seasoning salt by combining thyme, flaky salt and lemon zest in a small bowl. Mix gently. The salt mixture will be slightly wet and clumpy. When fish is done, sprinkle a little bit of the seasoning salt over each fillet, making sure each portion gets a bit of salt, zest and thyme.
Serve immediately with any remaining seasoning salt if desired.