Check items off while grocery shopping - it’s remembered here.
Take the rice out ahead of time to cool slightly, wrap in plastic wrap, press flat to about 1cm thick, and cut into bite-size pieces.
Heat oil and butter in a pan and fry the rice from step 1 on both sides until crisp, like frying.
Mix 2T mayonnaise, 1T mentaiko, oligo syrup, mirin, and a little pepper together to make the mentaiko mayo.
Top the rice from step 1 with 1/2T of the mentaiko mayo from step 3, chopped scallion, more mentaiko, and a little grana padano on top.