aged balsamic vinegar or balsamic vinegar reduction, for drizzling
Cut salmon fillet into two equal portions and brush both sides of each piece with olive oil. Sprinkle flesh side with salt, pepper and dried thyme. In a large skillet, heat one tablespoon olive oil and butter on medium-high until butter foams. Carefully place fillets flesh-side down in skillet. Cook without moving until edges begin to crisp, about 2 minutes. Decrease heat to medium and cook until fillets are golden brown, about 1 minute more. Turn fillets so they are skin-side down and continue cooking until medium-rare and skin is crisped, 5-7 minutes depending on their thickness. Add a few additional drops of olive oil as needed to prevent sticking. Remove fillets to serving plates and drizzle with balsamic vinegar. Serve immediately.