Nappa cabbage soup

I have no idea if the original recipe this is based on is actually a traditional Sichuan dish.  Whatever.

• 1 Nappa cabbage, tender light green part only (~2 lbs)
• 4 cups water
• 1 tablespoon coarse sea salt + more to taste
• OPTIONAL: 1 teaspoon sichuan peppercorns

Preheat the oven to 300F.  Cut the cabbage into quarters lengthwise.  Remove the tough root from each of the four segments, being otherwise careful to maintain the integrity of the pieces.  Heat a large iron skillet or equivalent that will fit the cabbage quarters.  Cook dry until charred, then rotate and repeat on the other cut side.  Once all pieces are charred, place in a heatproof dish with 4 cups of water and salt and peppercorns if using.  Braise, covered, for 2 hours or until the cabbage has disintegrated into the soup.  Adjust salt and eat.  That's it.  Really.  If you don't like the charred taste, just put everything into the oven from the get-go. .  Note: this gives you gas.