My answer to your question, Jane, is yes; whenever you don’t go and eat automatically, the addictive desire will tend to become more obvious. I get that you want to begin with this overeating while preparing meals, but it may well be tough to stay conscious throughout, so food may “find it’s way into your mouth” without you noticing just because it’s right there at your fingertips and your mind will wander on to other things most likely.
A few suggestions with this, and please try whatever you want to see what works best for you in this particular circumstance. One is for you to just take a finite space of time (1 minute, 5 minutes, 15 minutes – whatever challenges you a bit) where you intend to catch and think through your desire before you unconsciously satisfy it. So not the entire food prep for that meal, just a bit of it, with a strong intension to stay conscious at least for that time.
Another idea is to make it difficult to eat unconsciously by covering your mouth or holding something in your mouth. But only do this if you can see it as a free choice and maybe even a game.
One more thing is to not necessarily aim for an “all-or-none” result. Maybe put some snacks aside and fully intend to eat them while you are doing the prep, or before you start.
And finally, know that it will be SO easy for you to ‘go unconscious’ and eat without noticing, so be willing to FORGIVE YOURSELF for all of that and be willing to be on a learning curve. Aim to appreciate even a small, partial success – and then you can build on that over time.