Step 1

Combine the ground beef, finely chopped sweet onion, minced garlic, Worcestershire sauce, salt and pepper in a large bowl. Divide the mixture into fourths and shape each portion into a 1-inch-thick patty. Press your thumb into the center of each patty to create an indentation. Editor's Tip: Making an indentation in the centers of the burger patties helps prevent them from shrinking during cooking.

Step 2

Heat a large skillet over medium-high heat; place the patties in the hot pan with about two inches of space between them. Cook the burgers for four to five minutes, then flip them over to cook on the other side for another four to five minutes (the internal temperature should be 160°F). Transfer the burgers to a plate and cover them to keep them warm.

Step 3

Discard the excess grease from the pan and return the pan to the burner. Melt the butter over medium heat, then add in the diced sweet onion. Cook and stir the onion, scraping up browned bits from the bottom of the pan, until the onion is softened, for four to five minutes. Add the beef stock, Worcestershire sauce, soy sauce, salt and pepper to the pan and stir them together. Increase the heat to medium-high and bring the liquid to a simmer. Let it simmer for four to five minutes. In a small bowl, whisk the cornstarch with 2 tablespoons of cold water; add this mixture to the pan. Whisk the gravy constantly for two to three minutes or until it has thickened and become smooth. Move the pan off the heat.

Step 4

Heat a teaspoon of vegetable oil in a small, nonstick frying pan set over medium heat. When the oil is hot, crack an egg into the pan. Let the egg cook without moving or flipping it for two to three minutes. The whites should be set and the yolk still runny. Carefully transfer the egg to a plate; repeat these steps to cook the other three eggs.

Step 5

To serve the loco moco, add a cup of cooked rice to each bowl or plate. Top each with a burger and a generous pour of gravy. Add a sunny-side up egg to each dish, and garnish them with diced scallions. Serve the loco mocos immediately, while they're still hot!