INGREDIENTS
Serves: 4 (as a starter)
FOR THE DASHI
10 grams kombu (dried kelp)
1 litre filtered or soft water
30 grams dried shiitake mushrooms
FOR THE AGEDASHI TOFU
500 millilitres dashi stock
5 tablespoons light soy sauce
5 tablespoons mirin
400 grams soft or silken tofu (drained for 20 minutes)
6 tablespoons cornflour
vegetable oil (for deep-frying)
2 spring onions (finely sliced)
1 tablespoon grated daikon radish to serve (optional)
METHOD
FOR THE DASHI
Kombu comes in large sheets that require cutting down to size. Once you have weighed the amount of kombu that you need, I recommend that you make some extra cuts into the pieces with scissors to increase the surface area and help the flavour to release into the water.
Pour the measured filtered water into a large bowl or saucepan and add the kombu and shiitake mushrooms. Cover with clingfilm (plastic wrap) or a lid and leave for at least 2 hours or overnight.
Pour the mixture into a saucepan, if it is not already in one, and remove the mushrooms. Simmer over a medium-low heat until just before boiling, then remove the kombu. It is really important that you don't boil the kombu, or it loses its delicate flavours. My friend Tim Anderson, of Nanban Japanese restaurant in London, recommends toasting kombu over an open flame for a deeper flavour before soaking it.
The dashi can be kept in the refrigerator, covered, or in a closed bottle, for 3 days, or in the freezer for up to 2 months.
FOR THE AGEDASHI TOFU
Prepare the sauce by mixing the dashi, soy sauce and mirin together in a bowl.
Next, slice the tofu into 4 x 100g/3½ oz blocks and coat the pieces in the cornflour.
Fill a large saucepan or wok with enough oil to sit at least 2cm/¾ inch deep and heat it up for 3–4 minutes. As always when deep-frying, be very careful and do not leave the kitchen or take a telephone call.
Drop 2 of the tofu blocks into the oil; they should sizzle immediately. If they don’t, the oil is not hot enough. Fry for 3–4 minutes until lightly golden brown, then lift out onto kitchen paper (paper towels) to drain off the excess oil. Fry the remaining 2 pieces in the same way before serving up into bowls.
Divide the sauce between the bowls, pouring it around the tofu, not on top of it.
Scatter with spring onions and grated daikon to serve.