The line cook at a diner in Boise told me my soup tasted like a warm swimming pool, and he was right
This was about 4 years ago. I was working grill at this place off Vista Ave, maybe 30 covers a night. Quiet spot. This new kid Marcus comes in, fresh out of some culinary program, real confident. So one Tuesday I make my potato leek, taste it, think it's solid. I hand him a spoon. He takes one slurp and just stares at me. Then he goes, dead serious, like he's doing me a favor: 'This tastes like a warm swimming pool.' I was so mad. Then I tasted it again. Yeah. I'd been dumping in the water from the blanched leeks and never adjusting the salt to make up for it. He showed me to save that water and use it for stock instead. Took me 3 more shifts to get my salt right.
That kid quit a month later to go work at a food truck. I still think about that line every time I make soup. What's the most brutal true thing a coworker ever told you about your food?