Fish 101 on San Elijo Avenue in Encinitas's Cardiff-by-the-Sea is the second location of the sustainably focused seafood kitchen founded, which opened in early 2019 after the success of the Leucadia original. The counter-service menu runs the same Baja fish tacos, beer-battered rock cod fish-and-chips, and Thai-style yellow coconut seafood curry as the flagship, sourcing sustainably caught local fish and recycling cooking oil into biofuel — an environmental commitment that extends to compostable takeout containers, a level of sourcing transparency shared by few Cardiff-by-the-Sea restaurants beyond morning health-food kitchens like VG Donut & Bakery. White clam chowder with manila clams and smoked bacon opens the appetizer menu alongside ahi tuna poke and crispy calamari with lemon aïoli. The San Elijo Avenue location serves the Cardiff-by-the-Sea lunch crowd within walking distance of San Elijo Lagoon, drawing the same post-beach dining traffic that fuels the counter-service Mexican kitchens like El Pueblo Mexican Food in the 92007 ZIP code. The pastry program rotates seasonal desserts including the Capt'n Eli's root beer float and salted-caramel ice cream swirls, adding a dedicated sweets station to the fish-house format.