1. In a pressure cooking pot, heat vegetable oil until hot. Add garlic and fry until just fragrant. Add the onion and cook until lightly browned. Add the beef and cook for a few minutes.
2. Add the flour, stirring to combine with the onions. Then add the butter and melt it.
3. Pour the cooking sake and then water. Bring it to a boil.
4. Cover the lid and lock the pressure cooker. Turn the heat to high. Once the pressure builds up, turn the heat down to low heat and cook at high pressure for about 8 minutes. Turn off the heat and let the pressure come down naturally.
5. Remove the lid, add the seasoning (tomato paste, worcestershire sauce, ketchup, soy sauce, sugar and kosher salt ). Using a wooden spoon, mix gently.
6. Serve the steamed rice on the plate and pour the "hayashi sauce" over the rice.
7. Pour some heavy cream and sprinkle some green flakes to decorate if you like.