Of course I'm in the kitchen. I am dog.
Most dog owners are familiar with this scenario. Doing dishes or wiping the counter is lonely, lonely work, but as soon as the vegetables hit the cutting board, a close friend appears: dog. It doesn't seem to matter how much the chef begs or pleads, or if the dog ever, ever, snags some of that delicious human food.
So, what's up with that?
If you have ever seen dogs who find their dinner as scavengers from a dumpsite, you have seen part of the answer. If your dog's great-great-great-great-great-grandpa was not an efficient and capable scavenger, he may not have left behind any puppies to carry on his line. Polite, discerning dogs who stayed away from the scrap heap were not successful in the romance department. Your dog inherited this - "if there is food nearby, act and act quickly, KitchenDog! You may never get another chance." Many dogs simply do not need the payoff of occasional table scraps to keep up their eternal and hopeful kitchen vigilance. Although of course that helps.
Another part of the answer might be right in front of your dog's face: his nose. Are there scents you love? Freshly baked cinnamon buns, smoke from a campfire, a particular flower? If you would detour out of your way and take a few minutes to just enjoy a scent, you can imagine how your dog, with his powerful nose, would do the same. It is payoff enough to be close to those delicious smells.
That's all well and good, but I want him out of the kitchen!
There are a couple of ways to handle this issue. The easiest is to just shut your dog out of the kitchen. Bonus points if you can toss his evening meal all around the backyard for him to find or feed him in a stuff-able toy, which will scratch his scavenging itch.
You can also train him to stay outside of the kitchen while you cook. Call on a pro dog trainer or take an obedience class for this one, although you will get some mileage from just "catching" him being good. If he does eventually give up his hopeful quest and go lay down outside the kitchen, zip over with some of what you're cooking and give it to him. This seems counter-intuitive, and will likely result in him immediately returning to the kitchen. Be zen about it and wait. You'll see a trend of his hopeful behaviour becoming oriented more and more often to the spot where he gets fed. Then just stretch the amount of time he must stay out of the kitchen by a second or two each day.