In a small saucepan, combine shallot, bay leaf, and white wine. Simmer over medium heat until almost fully reduced.

Add crème fraîche and reduce by half, about 3–4 minutes.

Whisk in butter one tablespoon at a time until half the butter is incorporated. Remove from heat.

Off the heat, add remaining cold butter all at once and whisk vigorously to emulsify.

Season with lemon juice, lemon zest, and salt. Keep warm, stirring occasionally. Take on and off low heat to maintain emulsion if needed.

Pat salmon filets dry with a paper towel and season with kosher salt.

Heat a medium skillet over medium-high heat with a drizzle of olive oil.

Once hot, place salmon skin-side down. Press gently with your hand or a kitchen weight to ensure even skin contact.

Sear for 4–5 minutes, until skin is deeply golden and crispy. Flip and cook for another 1–2 minutes until just done.

Just before serving, gently whisk chive oil into the beurre blanc to "break" the sauce.

Plate the salmon skin-side up and spoon broken beurre blanc over the top or around the side.