Cut the ribeye into 1" cubes. Place in a bowl. Add soy sauce, dark soy sauce, oyster sauce, fish sauce and mix well. Cover and let marinate for 1 hour.
In a medium size bowl: add thinly sliced onions, salt, pepper, sugar, rice vinegar then mix everything together. Set aside until ready to eat.
Heat the skillet or pan to high heat. Add butter and wait until it melts. Add ribeye & sauce to the skillet. Cook for 5-6 minutes until sauce absorb to the meat. Also, make sure to stir occasionally. Remove meat from the heat source and transfer to the salad plate.