Step 1 Rinse 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 2 In 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.