01 - Heat vegetable oil in a large skillet over medium heat. Add the diced chicken and cook until no longer pink throughout.
02 - Add the onions and carrots to the skillet. Sauté until softened. Stir in the frozen peas and cook for 1 minute.
03 - Add the cold cooked rice, breaking apart any clumps. Stir well to combine with the vegetables and chicken.
04 - Pour in the ketchup and soy sauce, mixing thoroughly until the rice is evenly coated and heated through. Season with salt and pepper. Remove from the pan and shape the rice into two oval mounds on serving plates.
05 - In a bowl, whisk together the eggs, milk, and a pinch of salt until well combined.
06 - Melt 1 teaspoon of butter in a nonstick frying pan over medium-low heat. Pour in half of the egg mixture, swirling to coat the pan evenly. Cook, stirring gently, until the edges are set but the center remains slightly runny.
07 - Slide the omelette onto one of the shaped rice mounds, draping it over the rice to form a smooth covering.
08 - Repeat the omelette process with the remaining butter and egg mixture for the second serving. Drizzle extra ketchup over each omurice and garnish with chopped parsley if desired. Serve immediately.