Cook 1 cup of Japanese short-grain rice according to package instructions until fluffy. Melt 1 tablespoon of butter in a large skillet, sauté 1 chopped onion for 3 minutes, then add 1 cup diced chicken and cook until browned. Stir in 1 cup of vegetables and 2 tablespoons of ketchup, heating through.

Whisk together 4 fresh eggs with a pinch of salt until frothy. Heat a non-stick pan over low heat with 1 tablespoon of butter. Pour the egg mixture into the pan and swirl to coat. Cook for 3-4 minutes until the edges set, leaving the center slightly runny.

Add a generous portion of chicken rice onto one half of the omelette, then fold the omelette over the filling. Cook for an additional 1-2 minutes to warm the inside and keep the outside soft.

Slide the omurice onto a plate. Drizzle with extra ketchup or demi-glace, and garnish with parsley or cheese.