I love my mother-in-law, but she cannot stay out of the kitchen when she visits. She hovers while I cook, making comments like, "Wow, that's a lot of garlic." She salts and peppers dishes without asking for my permission and even flipped scallops I was sautéing before they had browned on each side. She'll wonder aloud, "What should we have for dinner?," and will even go out and buy groceries. I know she's trying to be helpful, but our cooking styles just don't mesh. How can I make her stay out of the kitchen and stop trying to control the menu?
Some people can only find validation through feeding others. If they're not allowed in the kitchen, they feel empty and lost. So don't even bother trying to persuade your mother-in-law to relax with a glass of wine. You have to find a way to let her help.
The solution is simple: Give her a task, but a completely separate one from yours. Don't worry, you needn't actually cook together, especially since, as you pointed out, people's cooking styles often don't jibe with their mothers-in-law's.
Maybe you're a freewheeling improviser and she follows recipes to the letter. Or you might feel that cleaning as you go trammels your creativity, whereas she's a hygiene freak. This was the case with Christopher Hirsheimer, a food editor and photographer, and her mother-in-law (now deceased). "She was fastidious about having one towel to dry your hands on and another to dry your dishes on, and she once told me how she terminated a friendship when she found out the woman washed her husband's socks in the kitchen sink. I wash [my] dog in the kitchen sink." Needless to say, it was stressful for the two women to share the kitchen.
One caveat: Make sure you give your mother-in-law something substantial to do, not some demeaning sous-chef task. It won't do much for her if she just chops the onions for your famous paella. She'll want to make a genuine contribution to dinner, so ask her for a signature dish she's proud of: "As a special favor tonight, would you make that delicious green bean salad of yours?" She'll be so busy topping and tailing the beans she won't have time to peer over your shoulder and ask why you're "overcooking" the scallops.
This way, it doesn't matter if you mince garlic with abandon and she prefers only the faintest whisper of it. You each have control over your own domain, be it entrée or dessert. It's a grown-up form of parallel play. And don't feel guilty about strategizing for her visit. When I explained your dilemma to readers of The Kitchn, many identified.
Kitchn reader Squirrely's advice was to relinquish your territory altogether: "My solution was to put aside my control issues, take some long walks, and say, hey, if this woman wants to fry things in my kitchen, serve it to me, then clean it all up, fine—she's here for five days, I can manage." rep_woman prefers getting all the cooking done in advance: "I try to have whatever we are going to eat ready to go so that it either goes in the oven or onto the grill as soon as my in-laws get to our house. That way, she has less reason to hover and drive me crazy!"
Occasionally, a task of her own won't be enough to distract your relative. Maybe nothing will make her stop peering over your shoulder and muttering, "You might want to chop those onions more finely" or "Do you really need that much salt?" In that case, banishment from the kitchen may be the only option. But do it gently. You can still assuage her need to help by giving her a food-related task; just find one she can execute in another room. Hirsheimer's solution: "I'd send her into the dining room and ask her to set the table … then people would say, 'Oh, what a beautiful table,' and I could say, 'Peggy did it.' She wasn't sitting in the kitchen anymore with her arms crossed and her tongue clucking."