Cover Wagyu in cling wrap and freeze flat until ready to use.
Remove meat from freezer and let rest for 10-15 minutes. Heat a hotplate to approximately 170C, add some oil.
Place carrot, asparagus and spinach on hot plate and cook until semi-cooked, season well and set aside.
Add a little more oil on hotplate and lay one meat portion gently on the hot plate. It will cook in about 2 minutes. Whilst cooking, lay carrot and asparagus lengthways on meat 5cm from edge and spread the spinach over the top. Fold meat over the filling and using the spatula roll up the meat until you have a cylinder. Repeat until all slices are cooked.
On the side melt the butter and add some soy, then using the spatula or a basting brush baste the roll. Season with salt and pepper.
Turn the roll so it faces you, and with the sharp knife cut in half and then each half in quarters so you have 8 pieces.
Using the spatula, stand each piece up. Plate in a row with the meat facing upwards and serve with a side salad.
CHEF’S TIPS Ask your butcher to trim and slice the Wagyu sirloin length ways into 3mm slices. 1 portion should be approximately 35cm by 20cm. You will need 4 overlapping slices to a weight of 200-250g total. You will also need a large long flat spatula (10-15 cm) and a very sharp long thin knife with no serrations.