Cook the Rice: Rinse rice under cool water until it runs clear. Add rice and water to a rice cooker and cook until done (or use stovetop method).

Make the Gravy: In a saucepan, whisk together beef stock, cornstarch, onion powder, shoyu, and beef bouillon paste. Cook over medium heat until thickened. Remove from heat and stir in heavy cream.

Prepare the Burger Patties: In a large bowl, combine ground beef, egg, onion, panko, ketchup, mayonnaise, salt, and pepper. Mix gently and shape into patties. Cook in a skillet over medium-high heat until browned and fully cooked, flipping once.

Cook the Eggs: Heat oil in a pan. Crack eggs into the pan, season with salt and pepper, and cook sunny-side-up (or over-easy if preferred).

Assemble the Loco Moco: Place a scoop of rice on each plate, top with a burger patty, pour over the gravy, and crown with a fried egg. Serve hot.