Make the Creamy Dill Sauce: Stir the sauce ingredients, minus the charred lemon juice, together in a small bowl and set aside. The charred lemon juice will follow.
Prep the Salmon: Line a small rimmed baking sheet with parchment paper (mine is a 1/8th sheet pan, 9 1/2" by 6 1/2" in size). Pat the salmon dry with a paper towel, then generously season the salmon on both sides with salt and pepper. Place the salmon skin side down onto the prepared baking sheet, and preheat the oven to 275 F. Let the salmon rest at room temperature while the oven preheats.
Bake the Salmon: Once the oven is to temp, drizzle one tablespoon of olive oil over the salmon. Bake the salmon at 275 F for 20 minutes. Halfway through cooking (after 10 minutes), carefully drizzle another teaspoon of olive oil over the salmon and continue cooking until the fish flakes apart easily and is cooked to your liking (the internal temperature will register 135 F to 140 F for medium).
Char the Lemons: While the salmon cooks, heat a small non-stick pan over medium-high heat. Pour in one teaspoon of avocado oil. Cut the zested lemon in half, and place the lemon halves cut side down into the hot pan. Cook the lemons without disturbing them for about 4-5 minutes until charred. Transfer them to a plate to cool.
Finish the Dill Sauce: Once cooled, squeeze one of the lemon halves into the dill sauce and stir to combine. Save the other half to squeeze over the cooked salmon OR cut it into wedges and serve it alongside the salmon.
Serve: Once the salmon is cooked, carefully transfer it to a small serving platter. Spread half of the dill sauce over the surface of the salmon. Tuck the charred lemon wedges next to the salmon, then serve immediately with extra sauce on the side.
Notes
This recipe will work for any salmon fillet ranging in size from 8 oz. to 14 oz. Adjust olive oil amounts as needed.