1 Combine miso, mirin, sugar and sake in a small pot. Bring to a boil, stirring frequently. Reduce heat to medium and cook for 7 minutes. Remove 5 tablespoons of the marinade, let cool, cover and set aside in the refrigerator. Pour the remaining miso marinade into a shallow baking dish and cool completely.
2 Rinse fish and pat dry. Place fish in the miso marinade and turn to coat. Cover dish with plastic wrap and refrigerate for 2 days to marinate.
3 Toast sesame seeds in a dry pan.
4 Grind sesame seeds in a mortar until oily. Peel and chop garlic. Add garlic to the sesame mixture and grind into a smooth paste.
5 Add soy sauce, rice vinegar and 1 pinch of sugar to the sesame paste mixture.
6 Rinse peas and cut lengthwise into very thin strips.
7 Remove fish from the marinade and pat dry.
8 Season fish with pepper. Heat oil in a skillet and sear fish on both sides.
9 Season fish with salt, place in a baking dish and bake in a preheated oven at 200°C (fan: 180°C, gas mark 3) (approximately 390°F/convection 350°F) for 10-13 minutes.
10 Cook the noodles according to package instructions. One minute before the pasta is done, add the snow peas. Drain in a sieve. Mix noodles with sesame mixture. Place noodles on plates and place the fish on top of the noodles. Drizzle with reserved 5 tablespoons of marinade and serve.