A corn arepa fried once, split open, filled with a raw egg and fried again until the egg sets inside. It is the breakfast of the Colombian Caribbean coast, and the seal is the part that goes wrong.
The seal is what decides whether this works. Egg that escapes through the opening spreads across the surface of the oil and burns, and the arepa comes out hollow. Use a small piece of dough, press it firmly over the cut, and lower the arepa into the oil seal-side up so gravity is on your side for the first few seconds. Two fryings, and the first one is the one that creates the pocket. The arepa puffs as it fries and the two walls separate, which is what leaves room for the egg. If it does not puff, it was rolled too thick. Crack the egg into a cup first rather than straight into the arepa. It gives you a chance to pour slowly and to stop if the opening is too small, and a broken yolk in the cup can be dealt with before it is inside anything. This is street food from the Caribbean coast, sold from carts in Cartagena and Barranquilla in the morning, and it is meant to be eaten within minutes of coming out of the oil.