Snap the woody ends off the asparagus, then cut the rest in half. Discard the woody parts.
Heat the oil in a large, non-stick frying pan. Add the asparagus and half of the lemon juice. Add a splash of water. Put a lid on and steam for a minute, then put the scallops in one by one, creating a circular pattern in the pan.
After 30 seconds add the remaining lemon juice and turn over the scallops starting with the first one you put in the pan, retracing the circle. Season with salt and pepper.
Add the herbs and serve immediately.