Make the soup base: Mix together the dashi, soy sauce, and salt. Set aside until needed.

Assemble the napa cabbage and pork: Trim off the ends of each napa cabbage leaf and layer each leaf with the thinly sliced pork belly. Try your best to cover the entire leaf. Repeat with all of the leaves except for one.

Stack the pork belly layered napa cabbage leaves on top of each other and finish by placing the extra napa cabbage leaf that's not layered with pork on top of the stack. Then, cut the stack into 2 inch pieces.

Packing the layered pork belly napa cabbage into a 5 inch donabe (clay pot) or a 3 quart saucepan. Start from the edge of the pot and work your way to the center. Try to keep everything tightly packed and keep the cut side of the cabbage up for the best aesthetics.

After packing in all the layered napa cabbage and have a little room, stuff a bundle of shimeji and/or enoki mushrooms in the center. Also, stuff the ginger slices in between the napa cabbage leaves. Lastly, place a shiitake mushroom and/or some carrot slices on top if you want.

Pour the seasoned dashi stock over the assembled cabbage and pork when ready to cook and cover with lid.

Place the pot of prepared mille feuille nabe over medium heat and bring it to a boil. Once at a boil, reduce the heat to a simmer and skim off any scum (optional). Allow the hot pot to cook for another 5 minutes or until the veggies and pork are cooked through.

While the hot pot is cooking, prepare the serving dish/bowl and sauce.

Once the hot pot is ready, bring it to the table and serve immediately. It'll be very hot, so be careful.

If there's broth leftover after finishing the mille feuille nabe, you can enjoy the now umami packed broth by simply adding some white rice or cook some udon noodles or even instant ramen in the broth.