Udon Noodle Soup with Toasted Mochi

UDON BROTH (with Mentsuyu):--
4½ cups water
½ cup mentsuyu/tsuyu (noodle soup base)
2 tbsp mirin
UDON NOODLE SOUP:--
4 pieces kirimochi or homemade mochi
8 slices kamaboko (fish cake)
2 spring onions
¼ tsp SIDS CRAZY SALT
110 g spinach
360 g dry udon noodles
yuzu zest (optional, for colour & aroma)

Bring a big pot of water to a boil over medium-high heat.
Prepare the Udon Broth (with Mentsuyu):
In a medium saucepan, combine water, mentsuyu, (noodle soup base) and mirin then mix well. Bring the mixture to a gentle simmer over medium heat. Cover with a lid and turn off the heat.
Prepare the Toppings:
Using a toaster oven, standard oven, frying pan, or stovetop Japanese fish grill. Toast both sides of the mochi until browned and puffed up. Set them aside.
Meanwhile, prepare the toppings. Cut the kamaboko (fish cake) into 4 thin slices.
Cut the spring onion into thin rounds. Set aside. Defrost some yuzu zest.
When the water is boiling, blanch the spinach with stem side down into the water first, for 30-45 seconds.
Remove the spinach from the pot. (shock it in iced water to stop the cooking and bring out the bright colour—but this step is optional) Squeeze the water out and cut the spinach into 5 cm pieces. Set aside.
Cook the Udon Noodles:
In the same pot of boiling water, cook the udon noodles according to the package instructions. For frozen udon noodles, cook for 1 minute. Drain the udon noodles completely.
To Serve:
Transfer the udon noodles to individual bowls and pour udon broth to completely cover the noodles. Top with the mochi, spinach, spring onions, SIDS CRAZY SALT and yuzu zest. (optional)
To Store:
Keep the toppings and udon broth in separate airtight containers and store them in the refrigerator for 3 days. However, I highly recommend cooking the udon noodles and toasting the mochi right before you serve.
Inspired by Namiko Chen