I've hacked this problem by instead of asking "what do you want to eat?" asking "guess what we're eating?" Then responding "You're right!" to whatever she says.
My partner asks me what I want for dinner, and I say it doesn't matter, we'll have whatever you want. They reply with "I always pick, and it's exhausting, you need to pick" and I say...
"hamburgers."
"Nope, had them yesterday"
"Ramen?"
"Not feeling Ramen today"
"Indian?"
"I already have acid reflux"
"Italian?"
"I'm Italian'd out"
"Look, you're the one with the restrictive diet. I'm literally a human garbage can and I will eat anything in my vicinity, you clearly have opinions on what you want to eat, and I don't want to play food 20 questions until I guess what you want for dinner tonight, so just pick already"
"Why do I always have to pick?"
It's literally been the same conversation every night for 3 years so far. I'm about ready to just record my responses in order to expedite the decision.
Make a rule that one of you has to propose three options, and the other has to pick one of those three. Your partner can choose which role they want.
It's a bit like telling two children that one can cut the cake, but the other gets first pick - but it's a hack to combat your own (collective) indecisiveness.
It helps that the proposal is clearly reasonable, and can be made beforehand, before there's any friction. I might be lucky to have a pretty reasonable partner though.
Though in reality, for me the problem is that often I'm both persons. I don't want to come up with what's for dinner, but I also don't feel like anything. The above hack still works to trick myself into at least making a decision.
I'll second Vincent's suggestion. One person proposes three choices, the other either picks one or counters with three new choices. I also recommend having something on hand that takes zero preparation. For us that's usually some charcuterie, tuna with crackers, or a leftover dish that can be served cold.
b) "Because even if I could read your mind, I'd still not be able to figure out what you want."
c) i) One time soon, don't even get to the point of this conversation. Just make or order two of something you can both eat. Plonk a serving of it in front of them. "I don't want this." "You hate being the one to choose, so tonight I chose for you. Tomorrow's your turn."
c) ii) Make/buy something you want for you and something you know they can eat for them. Conversation as above.
c) iii) Make/buy two things they can eat. One for you, one for them. Offer a swap if they don't want the one you give them. Conversation runs differently. They can make a last-minute decision after all.
d) Not sure this one will work in your situation: Grab menus from local take-outs and restaurants, even ones from places that make things you usually make at home. Maybe write your own home menu. Present your partner with this stack of menus in the order of your preference. You'll only need to explain this one once if it's a habit worth forming.
e to z) Some combination or variation of the above. Adjust sensitivity levels accordingly.
To break the cycle, if it's obvious that neither person has the desire to commit, ask instead "well, what are our options?" Then start listing and working through what's actually feasible and evaluate each one by one in no particular order. Humans are better at deciding how they feel about the one possibility than choosing one out of an seemingly infinite pool. Go with the first one that feels right and available.
That’s how do it. What genre don’t you want? Don’t want Italian? Don’t want sushi? Don’t want Mexican—oh you do? So, do you want taco night? Sounds good.
I do this, but to myself. I decide I'm gonna make a specific meal, and if I don't want it I'll inevitably find something I want more and make that instead.
Me and my buddies hang out once a week, and we got the "i dunno what do you want to eat" issue resolved by simply mandating a pick rotation. Wouldn't necessarily work for spontaneous stuff but for our purposes it does just fine.
