Preheat the oven to 200ºC / 400ºF
Using a medium-size mixing bowl add the miso paste, sesame oil, soy sauce, rice vinegar, maple syrup, and hot water. Mix all the ingredients until they are well combined.
To prepare the aubergines, cut them in halves lengthwise. Score the inside of the aubergine in squares making diagonal cuts. The cuts need to be deep but keeping the skin untouched.
Using a brush, marinate the aubergine with the miso glaze. Make sure enough sauce is used on each aubergine.
Place some baking paper on a baking tray, lay the marinated aubergines (facing up) and bake for around 30-40 minutes.
When the aubergines are cooked, take them out of the oven and drizzle some extra miso mixture on the top, add finely chopped onions and sprinkle some sesame seeds.