Chef John's Loco Moco

Ingredients (15)

• + 2 (4 ounce) patties ground beef add to pantry
• + 1 pinch salt and freshly ground black pepper to taste add to pantry
• + 1 pinch salt and freshly ground black pepper to taste add to pantry
• + 1 pinch cayenne pepper add to pantry
• + 1 ½ cups beef stock add to pantry
• + 4 teaspoons soy sauce add to pantry
• + 1 teaspoon Worcestershire sauce add to pantry
• + 2 drops sesame oil, or to taste add to pantry
• + 2 teaspoons ketchup add to pantry
• + 2 teaspoons white sugar add to pantry
• ✓ 4 teaspoons cornstarch
• + 2 teaspoons unsalted butter, divided add to pantry
• + 2 tablespoons minced green onions, white and light green parts only add to pantry
• + 2 eggs add to pantry
• + 2 cups hot cooked white rice add to pantry