Luquillo’s famous line of 60 or so beachfront friquitines (also known as quioscos, kioskos or just plain food stalls) along the western edge of Hwy 3 serve often-excellent food at very popular prices. It's a fine way to sample local food and snack culture, including scrumptious surullitos (fried cornmeal and cheese sticks).
Start by wandering past the dozens of choices to see what strikes your fancy. You'll find everything from outstanding comida criolla to top-notch burgers and Peruvian ceviche. All sell Medalla beer and most have full cocktail menus. The stalls themselves range from very basic to slightly stylish affairs. Most have kitchens on the parking side where you browse and tables on the beach side.
Two recommended choices are Terruño (kiosk 20) for creative local fare, and upscale La Parilla (kiosk 2), where seafood is the specialty.