Never had an issue with onions, or bean or anything else for that matter. I keep a cooler in my van and will bring whatever strikes me in the morning before I head out. Sandwich, or leftover pizza, yogurt, cheese and crackers, sometimes a salad it varies. Always have something cold to drink. Lately I had started putting a protein shake in the cooler.
Yeah that way I stay out of the drive up windows and I save a buck too. I'd rather have something from home anyway.
Like those dudes that give careful descriptions of their morning shave, including close up photos of everything on their sink?