sliced green onions and black sesame seeds, to serve
Cut the beef into thick strips. Mix the honey, ½ cup soy sauce, lemon juice, sake, ginger, garlic and sesame oil in a bowl, combine with the beef and refrigerate overnight. Drain, reserving the marinade, then thread the beef onto skewers.
Pour the marinade into a small saucepan and boil rapidly, until thickened.
Blanch and refresh the spinach, then squeeze out the water. Combine the dashi, mirin and remaining soy sauce in a small saucepan and boil rapidly, until reduced by three quarters. Mix with the spinach, then roll up into a thick log, then refrigerate.
Cook the skewers over moderate coal, then brush with some of the sauce. Serve with slices of spinach, the remaining sauce, green shallots and sesame seeds.