Preheat oven to 400 degrees.
Rinse fresh salmon fillets. Pat dry with paper towel.
Line baking pan (or sheet pan) with aluminum foil or parchment paper.
Place fillets in prepared baking dish skin down. Drizzle both sides with olive oil. Set aside.
In small bowl, combine ONE TABLESPOON of light brown sugar, salt, coarse ground black pepper, dried oregano, dried thyme, whole grain mustard, lemon juice, and 1-1/2 teaspoons of Liquid Smoke. Stir seasonings together until well combined. Taste a sample. If more flavor is desired, add additional one tablespoon of light brown sugar and 1/2 teaspoon of Liquid Smoke.
Coat both sides of fillets with the seasonings. Make sure fillets are skin side down.
Arrange six lemon slices around top, sides and bottom as shown in photo above.
Cover baking pan with foil. Bake 15 minutes. Remove baking pan from oven. Remove foil.
Return to oven without foil. Bake 10 more minutes to thicken glaze. When fillets are done, they will easily flake with a fork.
NOTE: Very thick fillets will take longer to bake. Adjust time accordingly.
Serve drizzled with hot glazes. Garnish with lemon slices (optional).