Crispy Skinned Fish with Herb Sauce

Name: Crispy-Skinned Fish with Herb Sauce
Ingredients: 2 oil-packed anchovy fillets (optional); 1 small garlic clove, thinly sliced; 1 cup chopped tender herbs (such as parsley, dill, and/or basil); 1 Tbsp. chopped pickles (capers, cornichons, or chile); 2 Tbsp. fresh lemon or lime juice or white wine vinegar; 6 Tbsp. (or more) extra-virgin olive oil, divided; Kosher salt, freshly ground pepper; 4 (5–6-oz.) skin-on black bass, striped bass, snapper, or salmon fillets; Flaky sea salt