Slice tofu into 8 cutlets. Lay tofu cutlets out on towel, put another towel on top and press down to remove water, then fry in a heavy skillet until golden brown.
Meanwhile, mix miso, sugar, sake, and mirin in food processor and pour over tofu cutlets. Turn tofu over to cover with marinade on all sides. Marinate overnight, or up to 2 days.
Before serving, cover bottom of heavy skillet with olive oil. Sauté leeks in olive oil until soft, about 10 minutes. Add Aji Mirin, and cook another 5 minutes. Puree leeks in food processor until smooth.
Place tofu cutlets on broiler pan and broil for a few minutes, until miso becomes caramelized. Spread pureed leeks on top of tofu and broil a few more minutes. Finish cooking in 375 degree oven for 10 minutes.
Recipe by iEatGreen at https://www.ieatgreen.com/recipe-miso-marinated-tofu-cutlets-with-leek-puree/