Fried Onions with Ponzu Sauce

method:

• Pour the mirin into a small saucepan and bring to the boil. Then turn down the heat and, over a low simmer, cook out the alcohol (about two minutes). Pour in the soy sauce and add the lemon juice. Under the tap, rinse away the fine sea salt from the kombu, and pop it in the sauce. Put the ponzu in the fridge and let the flavours combine for half an hour or so.
• In a large bowl, mix the plain flour, cornflour, sesame seeds and salt. Drop the egg into the middle and slowly add the water while whisking lightly with a balloon whisk. The batter should only be mixed just enough to incorporate the ingredients – any lumps of flour are fine left as they are.
• Peel the onion and cut into very fine sliced rings. Drop the onion rings into the batter and toss all together until thoroughly but lightly coated in a loose tangle.
• For the onions, heat the oil in a deep fat fryer or saucepan to 180C/350F. When the oil is at the correct temperature lift a small bundle of the onion rings with long handled metal tongs and lower them carefully in. Add two more bundles in exactly the same way. Cook the onions for about two minutes until crisp and golden, turning once.
• Transfer the tempura onions to a plate lined with kitchen paper using tongs. Leave to drain and stay warm in a low oven while you fry the rest or eat immediately and wait for more. Serve with the ponzu dipping sauce.