In a bowl, combine lemon zest, dill, chives, parsley, chervil, and black pepper. 
Sprinkle fillets with salt and then coat one side of each fillet with 1 teaspoon of Dijon mustard. 
Next, press the mustard-coated side into the lemon-herb mixture. 
Add the vegetable oil to a skillet over medium-heat. 
Place fillets, coated side down, into the hot oil. 
Cook for 3 to 3 1/2 minutes, or until crust turns golden.
Flip and cook for another 3 minutes, until fish flakes easily when scraped with a knife. 

Recipe adapted from Emeril Lagasse, Food Network