Given the background description of some cooking related query, summarize the question into a title
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Question: I'm going to make some sweet potato fries here shortly and I'm using a technique that I saw on television. I cut up my sweet potatoes into fries and I have been letting them soak in water. My intent is that some of the starch will dissolve into the water and help the fries crisp up better. Has anyone else tried this?

Answer: Soaking starches in water for better frying

Question: Many a recipe or package instructs: 'cook uncovered' without stating a reason. As a general matter, is this to protect me from boilover, or does it have some more subtle purpose?

Answer: When a recipe says, 'simmer uncovered', what's the issue?

Question: 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?

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