Remove leaves carefully from the base, wash and drain well. Don’t throw away any leaves that naturally came off while rinsing. We’ll use these leaves later on. If you happen to get a ginormous cabbage cut in half or quarters lengthwise. I usually buy small ones so I use the whole leaf. Pat them dry before next step.
Layer the pork belly and napa cabbage by placing one slice between each of the leaves. Cover leaves with pork belly, trim if necessary to fit. Repeat 3-4 times depending on size of pot.
Cut each napa cabbage wedge into 3-4 pieces each about 2 to 2½ inches (5-6 cm) long. Each section should not be taller than your cooking pot. Try to keep the layers of napa cabbage and pork belly neatly stacked as you slice.
Next, start stacking the ingredients in a donabe, hot pot, or regular 10-inch pot. I used a shallow Staub pot with the grill top. Turn the stacks on their side as you pack them so the pink and green layers are visible. Start from the outer edges of the pot and work your way toward the center. Place the thicker cabbage leaves near the outside edge and the tender leaves in the center. Make sure that you pack the pot tightly as the layers will become loose once the ingredients start to cook.
If you don’t have enough layers to pack the pot tightly, consider using a smaller pot or place other ingredients in the center. I Like to stuff enoki mushrooms or shimeji mushrooms in the center. Or use slices of radish to surround the mushrooms.
Make you dashi. Don’t reduce the salt If you are using dashi from packets since the napa cabbage will release liquid during cooking and dilute the soup. If using Shiro Dashi that is seasoned omit half the soy sauce and sake. Taste your broth, it should not be too salty.
Pour the broth into the pot with the napa cabbage and pork belly. Start cooking on high heat. Once boiling, skim off the foam and fat on the surface using a fine-mesh skimmer. Then, reduce the heat to medium low and cook covered until the napa cabbage is tender and the pork belly is cooked through, roughly 8-10 minutes.