
Bring a large pot of salted water to a boil.
Separate the white and green parts of the baby bok choy. Slice the white parts into thick pieces. Place in a colander and rinse well to remove any dirt or sediments. Drain.
Add the ramen to the boiling water and cook until al dente according to packet directions. About 1½ minutes before the noodles are ready, add the white parts of the baby bok choy and the corn. Just before everything is ready, throw in the green bok choy leaves and blanch until they are wilted, about 20 seconds. Drain immediately and refresh under cold running water, then leave to drain again. Let cool while you make the dressing.
Make the dan dan dressing: In a small bowl, whisk together the sesame paste, chile oil, soy sauce, vinegar, sugar and garlic until a chunky paste forms. Add 2 tablespoons of the milk and whisk, adding another tablespoon if needed, until the dressing is smooth and pourable. The dressing should be the consistency of cream. (The dressing can be prepared up to 2 days ahead and stored in a sealed jar or airtight container in the fridge. It will thicken up, so add a splash or two of milk or water to loosen it up before adding to the noodles.)
In a large shallow bowl, place the ramen noodles, greens and corn. Add the dressing and toss to coat. Top with the sesame seeds, scallions and a few drops of chile oil. Taste and season with salt if needed. Serve at room temperature.