In a cast iron skillet or frying pan, heat the oil on medium until hot but not smoking. Pan should sizzle a droplet of water.
Add the steak and sear for 3 minutes on each side or until a dark brown crust forms. Meanwhile, crush 4 of the garlic cloves with the skin left on.
Add the 4 garlic cloves and continuously flip the steak on either side for exactly 1 minute per side to ensure even cooking. Do this for about 8 to 10 minutes, ensuring to not overcook.
Add the butter and rosemary after 10 minutes and baste the steak with the butter and oil using a spoon.
Remove from heat after testing for doneness and let the steak rest for at least 10 minutes. Remove steak from pan and sprinkle with Pepper Salt to taste.
In the same pan as the steak, on high heat add a dash of olive oil. Stir-fry the onions for 3 minutes to caramelize. Add the mushrooms and cook for another 2 minutes.
Add the remaining vegetables and powders. Simmer on medium, adding the sauces while stirring. Simmer for another 5 minutes or until the sauce has reduced a little bit and the vegetables are cooked through. If the pan is too hot and the vegetables need more cooking time, add water.
Add the soba noodles and incorporate on low heat or off the heat if completely done.
Place the noodles on a plate. Cut the steak into strips and serve hot over the noodles.