Arepas are Venezuelan and Colombian architecture — the masa has to be the right hydration, the griddle has to be the right temperature, and the internal structure has to support the filling without becoming a bag. Kelvin Fernandez, who now runs Las Lap Rum Bar in New York and spent years as executive chef at La Marina before that, has been building that architecture long enough to understand where it fails.
Fernandez's masa runs at 65% hydration — wetter than the bag instructions, drier than instinct suggests — and is mixed three minutes before forming, which gives the precooked cornmeal time to fully hydrate and prevents cracking during the griddle stage. He cooks the arepas on a cast-iron comal at medium-high for four minutes per side to establish the crust, then finishes them in a 375°F oven for eight minutes, which sets the interior without burning the exterior. The filling goes in immediately after the cut, while the arepa is still hot enough to warm the ingredients on contact.
Bobby Flay has a long and distinguished history of cooking things on a grill. An arepa is not a thing you grill when you could use a comal, and the difference shows up in the crust.