Step 1Rinse and drain the Chinese broccoli. Remove the flowers. Keep the leaves whole and remove the tough part of the stalk. Wash the leaves, then drain and set aside.
Step 2In a heavy 6- or 8-quart saucepan, heat the oil over medium-high heat until almost smoking. Add the asafetida and sizzle for just a minute, until aromatic.
Step 3Add the dried chiles, one-half teaspoon salt, the baking soda and 3 cups of water. Bring to a rolling boil. Add the greens, stir well and cook over medium-high heat until done, about 10 minutes. Season again to taste if desired, drain excess liquid (through a colander or strainer) and discard. Serve immediately.