1 tbsp. extra-virgin olive oil or canola oil
½ tsp. fresh lemon juice
½ tsp. freshly grated lemon zest
1 tsp. capers, rinsed and finely chopped
1 tsp. finely chopped fresh parsley
2 tsp. finely chopped fresh chives
1 anchovy fillet, rinsed and finely chopped
1 tbsp. reduced-fat sour cream
3 tbsp. low-fat mayonnaise
⅛ tsp. freshly ground pepper, plus more to taste
¼ tsp. kosher or sea salt, plus a pinch, divided
½ tsp. finely chopped peeled fresh ginger
2 tbsp. chopped fresh cilantro
2 tbsp. finely chopped red onion or scallion
1 pound salmon fillet, preferably wild Pacific, skinned (see Tip)