Given the background description of some cooking related query, summarize the question into a title

Input: Consider Input: I am cooking for a large group and am trying to do as much as I can in advance. One thing I would love to do in advance is chop several onions. I have done this before with a single onion; I stored the chopped onion in a plastic storage container (sealed with the lid) in the fridge. About 6 hours later, the smell of onions was very strong both in the fridge and on everything that was in the fridge. I can't imagine it with 4-6 onions!What can I do to avoid the smell, not ruin everything in my fridge, but still be able to do the preparation 6-8 hours in advance?

Output: How can I store chopped onions in the fridge without the smell?


Input: Consider Input: Me and my friends have been cooking a 2kg=4.5 pounds piece of rumproast in a bbq smoker. We cooked it at about 250°F for about 3 hours. After that we, wrapped it in tin foil, raised the temperature to about 300°F and cooked it for an additional 3 hours. Our thinking here was that we can raise the temperature a bit, since the moisture can't escape anyway because it's wrapped in tin foil.We were hoping for a juicy and tender roast, that "tears apart" easily with a fork. At the end it wasn't tender and it was so dry that we were afraid it would suck the moisture out of the air... When we unwrapped the tin foil there was a lot of liquid (juice), that should've probably stayed in the meat? Was the temperature too high or wasn't the cooking time right? Is this even an appropriate piece of beef for "low and slow" smoking?

Output: Dry and Tough Rumproast


Input: Consider Input: I'm preparing the court-bouillon recipe from James Peterson's Sauces (p. 103 of 3rd edition). The procedure is, roughly:Sweat vegetables,Simmer vegetables for 10 minutes,Add white wine and vinegar, simmering for a further 15 to 20 minutes, and thenCool and strain.My question is about step 3. For what reasons would the wine and vinegar be withheld for the first 10 minutes of simmering? Is this an evaporation issue? Or is there some deeper interaction between wine/vinegar and vegetables to be accounted for?Thanks!


Output: Court-bouillon: Why delay adding the wine and vinegar?