First piece of advice, which you have already gotten several times, is DO NOT give in to the temptation to chase the pup. If you do it is game on. When you see the pup start to go into chase mode, simply turn and run the other way. It may work even better if you turn and run the other way just as she turns with the mark and spots you. That way, you can potentially avoid the whole chase thing and turn "here" into a fun game using the pup's natural instinct to chase movement. All the while making coming back to where you are the coolest thing ever. This is really the teaching part, as you are teaching the pup that coming back to you after picking up an object is just what the pup does - a natural behavior.
Then, get a 30 - 40' rope and make a loop on one end. When you pass the rope back through the loop, voila - a "choke rope." Throw short retrieves, and use short tugs on the rope to really start teaching the command. "Here" tug "here" a few times ought to do the trick. Then, if she reverts to old habits, do the same thing to start to enforce "here." Make sure you have some gloves on. Rope burn really hurts. This is really a mild force, so the second part of my mantra above. IOW, now that the pup knows he is supposed to come back to you on "here," we start to insist on it and in fact ingrain it - make it a compulsion instead of a desire, if that makes sense - because at some point we will want the pup to do this in the face of distractions. You eventually want your pup to have one thought in his head once the fetch object is in his mouth - "I have to get back there to my handler ASAP."
The reinforce would be eventually done with nicks as Evan pointed out previously, once you have CCd your pup. I would consider initially chaining the collar stimulus together with the rope tug - something the pup already understands - to make it as easy for him to understand the proper reaction to the collar pressure as possible. This will also help him understand that the pressure is comng from you, not some random event. It would also start to explain to him that he can turn pressure off with compliance, which FF will show him for sure.
Good luck with your pup.