Heat the grill to high
Add the spinach, butter, water and garlic to a blender and blitz until vivid green, about 1 minute
Rinse the sushi rice under cold water a few times until it runs clear, then drain
Add rice to a small saucepan with the spinach water and bring to the boil
Once boiling, cover with a tight-fitting lid, turn the heat down to low and cook for 12 minutes
Turn off the heat and leave to steam with lid on for another 12 minutes
In a mixing bowl, whisk together the miso, honey, soy sauce, lemon juice, MSG (if using), a pinch of salt and some black pepper
Slice each chicken thigh into three strips, then toss through the miso marinade
Lay out the chicken on a tray and spoon over any extra sauce
Grill for 6-8 minutes until charred and cooked through
Serve the spinach rice in bowls, top with the grilled chicken and spoon over any sauce from the tray
Finish with an egg yolk, chopped chives and a wedge of lemon
