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> fast with few ingredients Slice an onion. Slice mushrooms. Fry up with ground beef. Add a little water or soup stock or bone broth. Let simmer for a minute. Quick meal. Just one of a million examples for quick recipes that take minimal skill. You can even run the veggies through a chopper or food processor.
I often cook like that but pre-packaged fast-food is in fact faster to cook. I am not saying it should be eaten all the time, but the receipt you describe is not that fast. Mushrooms specifically are time consuming to clean in any non symbolic quantity. And you also need rice/potato with it unless you go keto in which case you need much more cleaning/slicing mushrooms and more meat.
FWIW, in my ~10 year professional cooking career I think I've washed a batch of mushrooms a grand total of 2 times, only because they were uncommonly dirty. You've probably eaten unwashed mushrooms many times in restaurants. Eating a little dirt probably isn't going to hurt you. If there's anything pathogenic on them a rinse in water isn't going to do much.