1. In a large cooking pot, add water (2L) and bring it to a boil, add "katsuodashi pack" if you have and simmer for about 5 min. Remove it from the water.
2. Add all the soup ingredients and bring it to a boil. Set aside.
3.Make the tenkasu In a small bowl, add flour, salt and water. Mix well. In a small cooking pot, add about 2 to 3 cm of oil and when the temperature reaches about 160℃, sprinkle the tenkasu batter, using a egg whisk.
4. Deep-fry until they are lightly browned. Transfer onto the paper towl to remove excess oil.
5. In a big cooking pot, add water and bring it to a boil. Add the soba noodles, and stir gently, so they don’t stick together. Cook until al dente or how hard you like your soba.
6. Drain the soba noodles and wash the noodles in cold water to get rid of any slimy texture.
7. Then put the soba noodles into the boiling water to warm up again. Once they are warm, drain well and place them into a serving bowl.
8. Pour the soup and sprinkle sliced leek as much as you want and then "Tenkasu".
1. Coat the block beef with olive oil, salt, pepper and garlic and let sit for about 30 min.
2. On a frypan, grill the beef (only its surface) on all sides until well browned.
3. Preheat your oven to 110℃ degrees.
4. Place the roast beef onto a baking dish. I usually put aluminium foil on the baking dish. Bake for 50min.
5. Wrap the roast up tightly in the foil and let it rest outside the oven at room temperature. While it is resting, it will continue to cook.
6. In the meantime, making the sauce In the same frying-pan (just remove any burnt garlic bits) fry the garlic until fragrant. Add shallot and cook until browned. Then add butter. Once the butter is melted, add all the other sauce ingredients (soy sauce, worcestershire sauce, sugar and mirin). Bring it to a boil and add olive oil (1 tbsp). Then transfer to your serving plate. Almost ready!
6. Using a sharp knife, slice the roast beef into thin slices (as per your taste) and serve with the sauce!