Heat a large skillet over medium heat, adding a tablespoon of oil. Sauté chicken, shrimp, or tofu for about 5 minutes until cooked, then add diced vegetables and stir for 3 minutes. Mix in cooked rice and demi-glace, cooking until heated thoroughly.

Beat 3-4 eggs in a bowl, adding a pinch of salt. In a non-stick pan, heat a teaspoon of oil over medium-low heat. Pour in the eggs and swirl the pan, allowing the edges to set for about 2 minutes while keeping the center runny.

Spoon the rice filling onto the omelet's center. Fold one side over the filling, then the other side to create a package. Slide the Omurice onto a plate.

Drizzle with ketchup or your favorite sauce and garnish with herbs or cheese. Serve immediately while hot.